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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// This is the browser side of the resource dispatcher, it receives requests
// from the child process (i.e. [Renderer, Plugin, Worker]ProcessHost), and
// dispatches them to URLRequests. It then forwards the messages from the
// URLRequests back to the correct process for handling.
// See
#include <stdint.h>
#include <map>
#include <memory>
#include <string>
#include <vector>
#include "base/callback_forward.h"
#include "base/gtest_prod_util.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "base/observer_list.h"
#include "base/optional.h"
#include "base/single_thread_task_runner.h"
#include "base/time/time.h"
#include "content/browser/blob_storage/chrome_blob_storage_context.h"
#include "content/browser/loader/resource_loader_delegate.h"
#include "content/common/content_export.h"
#include "content/public/browser/global_request_id.h"
#include "content/public/browser/global_routing_id.h"
#include "content/public/browser/resource_dispatcher_host.h"
#include "content/public/browser/resource_request_info.h"
#include "content/public/browser/stream_handle.h"
#include "content/public/common/previews_state.h"
#include "content/public/common/resource_type.h"
#include "net/base/load_states.h"
#include "net/base/request_priority.h"
#include "net/traffic_annotation/network_traffic_annotation.h"
#include "services/network/keepalive_statistics_recorder.h"
#include "services/network/public/mojom/url_loader.mojom.h"
#include "third_party/blink/public/mojom/fetch/fetch_api_request.mojom.h"
#include "url/gurl.h"
namespace base {
class OneShotTimer;
namespace net {
class HttpRequestHeaders;
class URLRequest;
class URLRequestContextGetter;
namespace network {
class ResourceScheduler;
class ScopedThrottlingToken;
} // namespace network
namespace storage {
class FileSystemContext;
namespace content {
class AppCacheNavigationHandleCore;
class AppCacheService;
class LoaderDelegate;
class NavigationUIData;
class ResourceContext;
class ResourceDispatcherHostDelegate;
class ResourceLoader;
class ResourceHandler;
class ResourceMessageDelegate;
class ResourceRequesterInfo;
class ResourceRequestInfoImpl;
class ServiceWorkerNavigationHandleCore;
struct NavigationRequestInfo;
struct Referrer;
struct ResourceRequest;
using CreateDownloadHandlerIntercept =
class CONTENT_EXPORT ResourceDispatcherHostImpl
: public ResourceDispatcherHost,
public ResourceLoaderDelegate {
// This constructor should be used if we want downloads to work correctly.
// TODO(ananta)
// Work on moving creation of download handlers out of
// ResourceDispatcherHostImpl.
CreateDownloadHandlerIntercept download_handler_intercept,
const scoped_refptr<base::SingleThreadTaskRunner>& io_thread_runner,
bool enable_resource_scheduler);
~ResourceDispatcherHostImpl() override;
// Returns the current ResourceDispatcherHostImpl. May return NULL if it
// hasn't been created yet.
static ResourceDispatcherHostImpl* Get();
// ResourceDispatcherHost implementation:
void SetDelegate(ResourceDispatcherHostDelegate* delegate) override;
void SetAllowCrossOriginAuthPrompt(bool value) override;
void RegisterInterceptor(const std::string& http_header,
const std::string& starts_with,
const InterceptorCallback& interceptor) override;
void ReprioritizeRequest(net::URLRequest* request,
net::RequestPriority priority) override;
// Puts the resource dispatcher host in an inactive state (unable to begin
// new requests). Cancels all pending requests.
void Shutdown();
// Force cancels any pending requests for the given |context|. This is
// necessary to ensure that before |context| goes away, all requests
// for it are dead.
void CancelRequestsForContext(ResourceContext* context);
// Cancels the given request if it still exists.
void CancelRequest(int child_id, int request_id);
// Returns the number of pending requests. This is designed for the unittests
int pending_requests() const {
return static_cast<int>(pending_loaders_.size());
// Intended for unit-tests only. Overrides the outstanding requests bound.
void set_max_outstanding_requests_cost_per_process(int limit) {
max_outstanding_requests_cost_per_process_ = limit;
void set_max_num_in_flight_requests_per_process(int limit) {
max_num_in_flight_requests_per_process_ = limit;
void set_max_num_in_flight_requests(int limit) {
max_num_in_flight_requests_ = limit;
// The average private bytes increase of the browser for each new pending
// request. Experimentally obtained.
static const int kAvgBytesPerOutstandingRequest = 4400;
// Called when a RenderViewHost is created.
static void OnRenderViewHostCreated(
int child_id,
int route_id,
net::URLRequestContextGetter* url_request_context_getter);
// Called when a RenderViewHost is deleted.
static void OnRenderViewHostDeleted(int child_id, int route_id);
// Called when a RenderViewHost starts or stops loading.
static void OnRenderViewHostSetIsLoading(int child_id,
int route_id,
bool is_loading);
// Force cancels any pending requests for the given process.
void CancelRequestsForProcess(int child_id);
void OnUserGesture();
// Retrieves a net::URLRequest. Must be called from the IO thread.
net::URLRequest* GetURLRequest(const GlobalRequestID& request_id);
void RemovePendingRequest(int child_id, int request_id);
// Causes all new requests for the route identified by |routing_id| to be
// blocked (not being started) until ResumeBlockedRequestsForRoute is called.
void BlockRequestsForRoute(const GlobalFrameRoutingId& global_routing_id);
// Resumes any blocked request for the specified route id.
void ResumeBlockedRequestsForRoute(
const GlobalFrameRoutingId& global_routing_id);
// Cancels any blocked request for the specified route id.
void CancelBlockedRequestsForRoute(
const GlobalFrameRoutingId& global_routing_id);
// Indicates whether third-party sub-content can pop-up HTTP basic auth
// dialog boxes.
bool allow_cross_origin_auth_prompt();
ResourceDispatcherHostDelegate* delegate() {
return delegate_;
// Must be called after the ResourceRequestInfo has been created
// and associated with the request.
// This is marked virtual so it can be overriden in testing.
// TODO(ananta)
// This method should be removed or moved outside this class.
virtual std::unique_ptr<ResourceHandler> CreateResourceHandlerForDownload(
net::URLRequest* request,
bool is_content_initiated,
bool must_download,
bool is_new_request);
// Called to determine whether the response to |request| should be intercepted
// and handled as a stream. Streams are used to pass direct access to a
// resource response to another application (e.g. a web page) without being
// handled by the browser itself. If the request should be intercepted as a
// stream, a StreamResourceHandler is returned which provides access to the
// response.
// This function must be called after the ResourceRequestInfo has been created
// and associated with the request. If |payload| is set to a non-empty value,
// the caller must send it to the old resource handler instead of cancelling
// it.
virtual std::unique_ptr<ResourceHandler> MaybeInterceptAsStream(
net::URLRequest* request,
network::ResourceResponse* response,
std::string* payload);
network::ResourceScheduler* scheduler() { return scheduler_.get(); }
// Called by a ResourceHandler when it's ready to start reading data and
// sending it to the renderer. Returns true if there are enough file
// descriptors available for the shared memory buffer. If false is returned,
// the request should cancel.
bool HasSufficientResourcesForRequest(net::URLRequest* request);
// Called by a ResourceHandler after it has finished its request and is done
// using its shared memory buffer. Frees up that file descriptor to be used
// elsewhere.
void FinishedWithResourcesForRequest(net::URLRequest* request);
// PlzNavigate: Begins a request for NavigationURLLoader. |loader| is the
// loader to attach to the leaf resource handler. |global_request_id| needs to
// be created by MakeGlobalRequestID() before calling this method.
void BeginNavigationRequest(
ResourceContext* resource_context,
net::URLRequestContext* request_context,
storage::FileSystemContext* upload_file_system_context,
const NavigationRequestInfo& info,
std::unique_ptr<NavigationUIData> navigation_ui_data,
network::mojom::URLLoaderClientPtr url_loader_client,
network::mojom::URLLoaderRequest url_loader_request,
ServiceWorkerNavigationHandleCore* service_worker_handle_core,
AppCacheNavigationHandleCore* appcache_handle_core,
uint32_t url_loader_options,
net::RequestPriority net_priority,
const GlobalRequestID& global_request_id);
int num_in_flight_requests_for_testing() const {
return num_in_flight_requests_;
// Sets the LoaderDelegate, which must outlive this object. Ownership is not
// transferred. The LoaderDelegate should be interacted with on the IO thread.
void SetLoaderDelegate(LoaderDelegate* loader_delegate);
void OnRenderFrameDeleted(const GlobalFrameRoutingId& global_routing_id);
// Called when loading a request with mojo.
void OnRequestResourceWithMojo(
ResourceRequesterInfo* requester_info,
int32_t routing_id,
int32_t request_id,
uint32_t options,
const network::ResourceRequest& request,
network::mojom::URLLoaderRequest mojo_request,
network::mojom::URLLoaderClientPtr url_loader_client,
const net::NetworkTrafficAnnotationTag& traffic_annotation);
// Helper function for initializing the |request| passed in. By initializing
// we mean setting the |referrer| on the |request|, associating the
// ResourceRequestInfoImpl structure with the |request|, etc.
// This function should be called for invoking the BeginURLRequest() function
// to initiate a URL request.
void InitializeURLRequest(net::URLRequest* request,
const Referrer& referrer,
bool is_download,
int render_process_host_id,
int render_view_routing_id,
int render_frame_routing_id,
PreviewsState previews_state,
ResourceContext* context);
// Helper function for initiating a URL request. The |is_download| and
// |is_content_initiated and |do_not_prompt_for_login| parameters are
// specific to download requests.
// TODO(ananta)
// Look into a better way of passing these parameters in.
// Please note that the InitializeURLRequest() function needs to be called
// called to initialize the request before calling this function.
void BeginURLRequest(std::unique_ptr<net::URLRequest> request,
std::unique_ptr<ResourceHandler> handler,
bool is_download,
bool is_content_initiated,
bool do_not_prompt_for_login,
ResourceContext* context);
bool is_shutdown() const { return is_shutdown_; }
// Creates a new request ID for browser initiated requests. See the comments
// of |request_id_| for the details. Must be called on the IO thread.
int MakeRequestID();
// Creates a new global request ID for browser initiated requests. The ID
// is consistent with the request id created by MakeRequestID(). Must be
// called on the IO thread.
GlobalRequestID MakeGlobalRequestID();
// Cancels a request as requested by a renderer. This function is called when
// a mojo connection is lost.
// Note that this cancel is subtly different from the other CancelRequest
// methods in this file, which also tear down the loader.
void CancelRequestFromRenderer(GlobalRequestID request_id);
scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner() const {
return io_thread_task_runner_;
scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner() const {
return main_thread_task_runner_;
network::KeepaliveStatisticsRecorder* keepalive_statistics_recorder() {
return &keepalive_statistics_recorder_;
// Checks if needs to prompt for login.
bool DoNotPromptForLogin(ResourceType resource_type,
const GURL& url,
const GURL& site_for_cookies);
class ScheduledResourceRequestAdapter;
friend class NetworkServiceClient;
friend class ResourceDispatcherHostTest;
FRIEND_TEST_ALL_PREFIXES(ResourceDispatcherHostTest, CancelRequestsForRoute);
FRIEND_TEST_ALL_PREFIXES(ResourceDispatcherHostTest, LoadInfo);
FRIEND_TEST_ALL_PREFIXES(ResourceDispatcherHostTest, LoadInfoSamePriority);
FRIEND_TEST_ALL_PREFIXES(ResourceDispatcherHostTest, LoadInfoUploadProgress);
FRIEND_TEST_ALL_PREFIXES(ResourceDispatcherHostTest, LoadInfoTwoRenderViews);
struct OustandingRequestsStats {
int memory_cost;
int num_requests;
friend class ShutdownTask;
friend class ResourceMessageDelegate;
// Information about status of a ResourceLoader.
struct CONTENT_EXPORT LoadInfo {
LoadInfo(const LoadInfo& other);
ResourceRequestInfo::WebContentsGetter web_contents_getter;
// Comes directly from GURL::host() to avoid copying an entire GURL between
// threads.
std::string host;
net::LoadStateWithParam load_state;
uint64_t upload_position;
uint64_t upload_size;
// Map from WebContents* to the "most interesting" LoadState.
typedef std::map<WebContents*, LoadInfo> LoadInfoMap;
typedef std::vector<LoadInfo> LoadInfoList;
// Information about a HTTP header interceptor.
struct HeaderInterceptorInfo {
// Structure is sufficiently complicated to require the constructor
// destructor definitions in the cc file.
HeaderInterceptorInfo(const HeaderInterceptorInfo& other);
// Used to prefix match the value of the http header.
std::string starts_with;
// The interceptor.
InterceptorCallback interceptor;
// Map from HTTP header to its information HeaderInterceptorInfo.
typedef std::map<std::string, HeaderInterceptorInfo> HeaderInterceptorMap;
// ResourceLoaderDelegate implementation:
scoped_refptr<LoginDelegate> CreateLoginDelegate(
ResourceLoader* loader,
net::AuthChallengeInfo* auth_info) override;
bool HandleExternalProtocol(ResourceLoader* loader, const GURL& url) override;
void DidStartRequest(ResourceLoader* loader) override;
void DidReceiveRedirect(ResourceLoader* loader,
const GURL& new_url,
network::ResourceResponse* response) override;
void DidReceiveResponse(ResourceLoader* loader,
network::ResourceResponse* response) override;
void DidFinishLoading(ResourceLoader* loader) override;
// An init helper that runs on the IO thread.
void OnInit();
// A shutdown helper that runs on the IO thread.
void OnShutdown();
// Helper function for URL requests.
void BeginRequestInternal(
std::unique_ptr<net::URLRequest> request,
std::unique_ptr<ResourceHandler> handler,
bool is_initiated_by_fetch_api,
std::unique_ptr<network::ScopedThrottlingToken> throttling_token);
void StartLoading(ResourceRequestInfoImpl* info,
std::unique_ptr<ResourceLoader> loader);
// We keep track of how much memory each request needs and how many requests
// are issued by each renderer. These are known as OustandingRequestStats.
// Memory limits apply to all requests sent to us by the renderers. There is a
// limit for each renderer. File descriptor limits apply to requests that are
// receiving their body. These are known as in-flight requests. There is a
// global limit that applies for the browser process. Each render is allowed
// to use up to a fraction of that.
// Returns the OustandingRequestsStats for |info|'s renderer, or an empty
// struct if that renderer has no outstanding requests.
OustandingRequestsStats GetOutstandingRequestsStats(
const ResourceRequestInfoImpl& info);
// Updates |outstanding_requests_stats_map_| with the specified |stats| for
// the renderer that made the request in |info|.
void UpdateOutstandingRequestsStats(const ResourceRequestInfoImpl& info,
const OustandingRequestsStats& stats);
// Called every time an outstanding request is created or deleted. |count|
// indicates whether the request is new or deleted. |count| must be 1 or -1.
OustandingRequestsStats IncrementOutstandingRequestsMemory(
int count,
const ResourceRequestInfoImpl& info);
// Called when an in flight request allocates or releases a shared memory
// buffer. |count| indicates whether the request is issuing or finishing.
// |count| must be 1 or -1.
OustandingRequestsStats IncrementOutstandingRequestsCount(
int count,
ResourceRequestInfoImpl* info);
// Estimate how much heap space |request| will consume to run.
static int CalculateApproximateMemoryCost(net::URLRequest* request);
// Force cancels any pending requests for the given route id. This method
// acts like CancelRequestsForProcess when the |route_id| member of
// |routing_id| is MSG_ROUTING_NONE.
void CancelRequestsForRoute(const GlobalFrameRoutingId& global_routing_id);
// The list of all requests that we have pending. This list is not really
// optimized, and assumes that we have relatively few requests pending at once
// since some operations require brute-force searching of the list.
// It may be enhanced in the future to provide some kind of prioritization
// mechanism. We should also consider a hashtable or binary tree if it turns
// out we have a lot of things here.
using LoaderMap = std::map<GlobalRequestID, std::unique_ptr<ResourceLoader>>;
// Deletes the pending request identified by the iterator passed in.
// This function will invalidate the iterator passed in. Callers should
// not rely on this iterator being valid on return.
void RemovePendingLoader(const LoaderMap::iterator& iter);
// This function returns true if the LoadInfo of |a| is "more interesting"
// than the LoadInfo of |b|. The load that is currently sending the larger
// request body is considered more interesting. If neither request is
// sending a body (Neither request has a body, or any request that has a body
// is not currently sending the body), the request that is further along is
// considered more interesting.
// This takes advantage of the fact that the load states are an enumeration
// listed in the order in which they usually occur during the lifetime of a
// request, so states with larger numeric values are generally further along
// toward completion.
// For example, by this measure "tranferring data" is a more interesting state
// than "resolving host" because when transferring data something is being
// done that corresponds to changes that the user might observe, whereas
// waiting for a host name to resolve implies being stuck.
static bool LoadInfoIsMoreInteresting(const LoadInfo& a, const LoadInfo& b);
// Picks the most interesting LoadInfos from the given array per WebContents
// and calls the delegate with them.
static void UpdateLoadStateOnUI(LoaderDelegate* loader_delegate,
std::unique_ptr<LoadInfoList> infos);
// Returns the most interesting LoadInfos from the given array per
// WebContents.
static std::unique_ptr<LoadInfoMap> PickMoreInterestingLoadInfos(
std::unique_ptr<LoadInfoList> infos);
// Gets the most interesting LoadInfos for each GlobalFrameRoutingIds.
// Includes the LoadInfo for all navigation requests, which may not have valid
// frame ids.
// We aggregate per-frame on the IO thread, and per-WebContents on the UI
// thread. The IO thread aggregation is used to avoid copying state for every
// request across threads.
std::unique_ptr<LoadInfoList> GetInterestingPerFrameLoadInfos();
// Checks all pending requests and updates the load info if necessary.
void UpdateLoadInfo();
// Invoked on the IO thread once load state has been updated on the UI thread,
// starts timer call UpdateLoadInfo() again, if needed.
void AckUpdateLoadInfo();
// Starts the timer to call UpdateLoadInfo(), if timer isn't already running,
// |waiting_on_load_state_ack_| is false, and there are live ResourceLoaders.
void MaybeStartUpdateLoadInfoTimer();
// Resumes or cancels (if |cancel_requests| is true) any blocked requests.
void ProcessBlockedRequestsForRoute(
const GlobalFrameRoutingId& global_routing_id,
bool cancel_requests);
void OnRequestResourceInternal(
ResourceRequesterInfo* requester_info,
int routing_id,
int request_id,
bool is_sync_load,
const network::ResourceRequest& request_data,
uint32_t url_loader_options,
network::mojom::URLLoaderRequest mojo_request,
network::mojom::URLLoaderClientPtr url_loader_client,
const net::NetworkTrafficAnnotationTag& traffic_annotation);
bool IsRequestIDInUse(const GlobalRequestID& id) const;
void BeginRequest(ResourceRequesterInfo* requester_info,
int request_id,
const network::ResourceRequest& request_data,
bool is_sync_load,
int route_id,
uint32_t url_loader_options,
network::mojom::URLLoaderRequest mojo_request,
network::mojom::URLLoaderClientPtr url_loader_client,
const net::NetworkTrafficAnnotationTag& traffic_annotation);
// There are requests which need decisions to be made like the following:
// Whether the presence of certain HTTP headers like the Origin header are
// valid, etc. These requests may need to be aborted based on these
// decisions which could be time consuming. We allow for these decisions
// to be made asynchronously. The request proceeds when we hear back from
// the interceptors about whether to continue or not.
// The |interceptor_result| indicates whether the request should be continued
// or aborted, and in the latter case whether the renderer should be killed.
void ContinuePendingBeginRequest(
scoped_refptr<ResourceRequesterInfo> requester_info,
int request_id,
const network::ResourceRequest& request_data,
bool is_sync_load,
int route_id,
const net::HttpRequestHeaders& headers,
uint32_t url_loader_options,
network::mojom::URLLoaderRequest mojo_request,
network::mojom::URLLoaderClientPtr url_loader_client,
BlobHandles blob_handles,
const net::NetworkTrafficAnnotationTag& traffic_annotation,
HeaderInterceptorResult interceptor_result);
// Creates a ResourceHandler to be used by BeginRequest() for normal resource
// loading.
std::unique_ptr<ResourceHandler> CreateResourceHandler(
ResourceRequesterInfo* requester_info,
net::URLRequest* request,
const network::ResourceRequest& request_data,
int route_id,
int child_id,
ResourceContext* resource_context,
uint32_t url_loader_options,
network::mojom::URLLoaderRequest mojo_request,
network::mojom::URLLoaderClientPtr url_loader_client);
// Wraps |handler| in the standard resource handlers for normal resource
// loading and navigation requests. This adds MimeTypeResourceHandler and
// ResourceThrottles.
std::unique_ptr<ResourceHandler> AddStandardHandlers(
net::URLRequest* request,
ResourceType resource_type,
ResourceContext* resource_context,
network::mojom::FetchRequestMode fetch_request_mode,
blink::mojom::RequestContextType fetch_request_context_type,
uint32_t url_loader_options,
AppCacheService* appcache_service,
int child_id,
int route_id,
std::unique_ptr<ResourceHandler> handler);
// Creates ResourceRequestInfoImpl for a download or page save.
// |download| should be true if the request is a file download.
ResourceRequestInfoImpl* CreateRequestInfo(
int child_id,
int render_view_route_id,
int render_frame_route_id,
PreviewsState previews_state,
bool download,
ResourceContext* context);
// Relationship of resource being authenticated with the top level page.
enum HttpAuthRelationType {
HTTP_AUTH_RELATION_TOP, // Top-level page itself
HTTP_AUTH_RELATION_SAME_DOMAIN, // Sub-content from same domain
HTTP_AUTH_RELATION_BLOCKED_CROSS, // Blocked Sub-content from cross domain
HTTP_AUTH_RELATION_ALLOWED_CROSS, // Allowed Sub-content per command line
HttpAuthRelationType HttpAuthRelationTypeOf(const GURL& request_url,
const GURL& first_party);
ResourceLoader* GetLoader(const GlobalRequestID& id) const;
ResourceLoader* GetLoader(int child_id, int request_id) const;
// Consults the RendererSecurity policy to determine whether the
// ResourceDispatcherHostImpl should service this request. A request might
// be disallowed if the renderer is not authorized to retrieve the request
// URL or if the renderer is attempting to upload an unauthorized file.
bool ShouldServiceRequest(int child_id,
const network::ResourceRequest& request_data,
const net::HttpRequestHeaders& headers,
ResourceRequesterInfo* requester_info,
ResourceContext* resource_context);
// Notifies the ResourceDispatcherHostDelegate about a download having
// started. The function returns the |handler| passed in, if the download
// is not throttled. If the download is to be throttled (Decided by the
// delegate) the function returns a ThrottlingResourceHandler to handle the
// download.
std::unique_ptr<ResourceHandler> HandleDownloadStarted(
net::URLRequest* request,
std::unique_ptr<ResourceHandler> handler,
bool is_content_initiated,
bool must_download,
bool is_new_request);
void RunAuthRequiredCallback(
GlobalRequestID request_id,
const base::Optional<net::AuthCredentials>& credentials);
static void RecordFetchRequestMode(const GURL& url,
base::StringPiece method,
network::mojom::FetchRequestMode mode);
static net::NetworkTrafficAnnotationTag GetTrafficAnnotation();
LoaderMap pending_loaders_;
// A timer that periodically calls UpdateLoadInfo while |pending_loaders_| is
// not empty, at least one RenderViewHost is loading, and not waiting on an
// ACK from the UI thread for the last sent LoadInfoList.
std::unique_ptr<base::OneShotTimer> update_load_info_timer_;
// True if a LoadInfoList has been sent to the UI thread, but has yet to be
// acknowledged.
bool waiting_on_load_state_ack_ = false;
// Request ID for browser initiated requests. request_ids generated by
// child processes are counted up from 0, while browser created requests
// start at -2 and go down from there. (We need to start at -2 because -1 is
// used as a special value all over the resource_dispatcher_host for
// uninitialized variables.) This way, we no longer have the unlikely (but
// observed in the real world!) event where we have two requests with the same
// request_id_.
int request_id_;
// True if the resource dispatcher host has been shut down.
bool is_shutdown_;
const bool enable_resource_scheduler_;
using BlockedLoadersList = std::vector<std::unique_ptr<ResourceLoader>>;
using BlockedLoadersMap =
std::map<GlobalFrameRoutingId, std::unique_ptr<BlockedLoadersList>>;
BlockedLoadersMap blocked_loaders_map_;
// Maps the child_ids to the approximate number of bytes
// being used to service its resource requests. No entry implies 0 cost.
typedef std::map<int, OustandingRequestsStats> OutstandingRequestsStatsMap;
OutstandingRequestsStatsMap outstanding_requests_stats_map_;
// |num_in_flight_requests_| is the total number of requests currently issued
// summed across all renderers.
int num_in_flight_requests_;
// |max_num_in_flight_requests_| is the upper bound on how many requests
// can be in flight at once. It's based on the maximum number of file
// descriptors open per process. We need a global limit for the browser
// process.
int max_num_in_flight_requests_;
// |max_num_in_flight_requests_| is the upper bound on how many requests
// can be issued at once. It's based on the maximum number of file
// descriptors open per process. We need a per-renderer limit so that no
// single renderer can hog the browser's limit.
int max_num_in_flight_requests_per_process_;
// |max_outstanding_requests_cost_per_process_| is the upper bound on how
// many outstanding requests can be issued per child process host.
// The constraint is expressed in terms of bytes (where the cost of
// individual requests is given by CalculateApproximateMemoryCost).
// The total number of outstanding requests is roughly:
// (max_outstanding_requests_cost_per_process_ /
// kAvgBytesPerOutstandingRequest)
int max_outstanding_requests_cost_per_process_;
// Time of the last user gesture. Stored so that we can add a load
// flag to requests occurring soon after a gesture to indicate they
// may be because of explicit user action.
base::TimeTicks last_user_gesture_time_;
ResourceDispatcherHostDelegate* delegate_;
LoaderDelegate* loader_delegate_;
bool allow_cross_origin_auth_prompt_;
std::unique_ptr<network::ResourceScheduler> scheduler_;
// Used to invoke an interceptor for the HTTP header.
HeaderInterceptorMap http_header_interceptor_map_;
network::KeepaliveStatisticsRecorder keepalive_statistics_recorder_;
// Points to the registered download handler intercept.
CreateDownloadHandlerIntercept create_download_handler_intercept_;
// Task runner for the main thread.
scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
// Task runner for the IO thead.
scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner_;
// Used on the IO thread to allow PostTaskAndReply replies to the IO thread
// to be abandoned if they run after OnShutdown().
base::WeakPtrFactory<ResourceDispatcherHostImpl> weak_factory_on_io_;
} // namespace content