content/shell/browser/shell_devtools_bindings.cc - chromium/src - Git at Google

 // Copyright 2017 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.

 #include "content/shell/browser/shell_devtools_bindings.h"

 #include <stddef.h>

 #include <utility>

 #include "base/guid.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/json/string_escape.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/storage_partition.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/content_client.h"
 #include "content/shell/browser/shell.h"
 #include "content/shell/browser/shell_browser_context.h"
 #include "content/shell/browser/shell_browser_main_parts.h"
 #include "content/shell/browser/shell_content_browser_client.h"
 #include "content/shell/browser/shell_devtools_manager_delegate.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/http/http_response_headers.h"
 #include "net/traffic_annotation/network_traffic_annotation.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_fetcher_response_writer.h"

 #if !defined(OS_ANDROID)
 #include "content/public/browser/devtools_frontend_host.h"
 #endif

 namespace content {

 namespace {

 // ResponseWriter -------------------------------------------------------------

 class ResponseWriter : public net::URLFetcherResponseWriter {
  public:
   ResponseWriter(base::WeakPtr<ShellDevToolsBindings> devtools_bindings_,
                  int stream_id);
   ~ResponseWriter() override;

   // URLFetcherResponseWriter overrides:
   int Initialize(const net::CompletionCallback& callback) override;
   int Write(net::IOBuffer* buffer,
             int num_bytes,
             const net::CompletionCallback& callback) override;
   int Finish(int net_error, const net::CompletionCallback& callback) override;

  private:
   base::WeakPtr<ShellDevToolsBindings> devtools_bindings_;
   int stream_id_;

   DISALLOW_COPY_AND_ASSIGN(ResponseWriter);
 };

 ResponseWriter::ResponseWriter(
     base::WeakPtr<ShellDevToolsBindings> shell_devtools,
     int stream_id)
     : devtools_bindings_(shell_devtools), stream_id_(stream_id) {}

 ResponseWriter::~ResponseWriter() {}

 int ResponseWriter::Initialize(const net::CompletionCallback& callback) {
   return net::OK;
 }

 int ResponseWriter::Write(net::IOBuffer* buffer,
                           int num_bytes,
                           const net::CompletionCallback& callback) {
   std::string chunk = std::string(buffer->data(), num_bytes);
   if (!base::IsStringUTF8(chunk))
     return num_bytes;

   base::Value* id = new base::Value(stream_id_);
   base::Value* chunkValue = new base::Value(chunk);

   content::BrowserThread::PostTask(
       content::BrowserThread::UI, FROM_HERE,
       base::BindOnce(&ShellDevToolsBindings::CallClientFunction,
                      devtools_bindings_, "DevToolsAPI.streamWrite",
                      base::Owned(id), base::Owned(chunkValue), nullptr));
   return num_bytes;
 }

 int ResponseWriter::Finish(int net_error,
                            const net::CompletionCallback& callback) {
   return net::OK;
 }

 }  // namespace

 // This constant should be in sync with
 // the constant at devtools_ui_bindings.cc.
 const size_t kMaxMessageChunkSize = IPC::Channel::kMaximumMessageSize / 4;

 void ShellDevToolsBindings::InspectElementAt(int x, int y) {
   if (agent_host_) {
     agent_host_->InspectElement(this, x, y);
   } else {
     inspect_element_at_x_ = x;
     inspect_element_at_y_ = y;
   }
 }

 ShellDevToolsBindings::ShellDevToolsBindings(WebContents* devtools_contents,
                                              WebContents* inspected_contents,
                                              ShellDevToolsDelegate* delegate)
     : WebContentsObserver(devtools_contents),
       inspected_contents_(inspected_contents),
       delegate_(delegate),
       inspect_element_at_x_(-1),
       inspect_element_at_y_(-1),
       weak_factory_(this) {}

 ShellDevToolsBindings::~ShellDevToolsBindings() {
   for (const auto& pair : pending_requests_)
     delete pair.first;
   if (agent_host_)
     agent_host_->DetachClient(this);
 }

 void ShellDevToolsBindings::ReadyToCommitNavigation(
     NavigationHandle* navigation_handle) {
 #if !defined(OS_ANDROID)
   content::RenderFrameHost* frame = navigation_handle->GetRenderFrameHost();
   if (navigation_handle->IsInMainFrame()) {
     frontend_host_.reset(DevToolsFrontendHost::Create(
         frame,
         base::Bind(&ShellDevToolsBindings::HandleMessageFromDevToolsFrontend,
                    base::Unretained(this))));
     return;
   }
   std::string origin = navigation_handle->GetURL().GetOrigin().spec();
   auto it = extensions_api_.find(origin);
   if (it == extensions_api_.end())
     return;
   std::string script = base::StringPrintf("%s(\"%s\")", it->second.c_str(),
                                           base::GenerateGUID().c_str());
   DevToolsFrontendHost::SetupExtensionsAPI(frame, script);
 #endif
 }

 void ShellDevToolsBindings::Attach() {
   if (agent_host_)
     agent_host_->DetachClient(this);
   agent_host_ = DevToolsAgentHost::GetOrCreateFor(inspected_contents_);
   agent_host_->AttachClient(this);
   if (inspect_element_at_x_ != -1) {
     agent_host_->InspectElement(this, inspect_element_at_x_,
                                 inspect_element_at_y_);
     inspect_element_at_x_ = -1;
     inspect_element_at_y_ = -1;
   }
 }

 void ShellDevToolsBindings::WebContentsDestroyed() {
   if (agent_host_) {
     agent_host_->DetachClient(this);
     agent_host_ = nullptr;
   }
 }

 void ShellDevToolsBindings::HandleMessageFromDevToolsFrontend(
     const std::string& message) {
   std::string method;
   base::ListValue* params = nullptr;
   base::DictionaryValue* dict = nullptr;
   std::unique_ptr<base::Value> parsed_message = base::JSONReader::Read(message);
   if (!parsed_message || !parsed_message->GetAsDictionary(&dict) ||
       !dict->GetString("method", &method)) {
     return;
   }
   int request_id = 0;
   dict->GetInteger("id", &request_id);
   dict->GetList("params", &params);

   if (method == "dispatchProtocolMessage" && params && params->GetSize() == 1) {
     std::string protocol_message;
     if (!agent_host_ || !params->GetString(0, &protocol_message))
       return;
     agent_host_->DispatchProtocolMessage(this, protocol_message);
   } else if (method == "loadCompleted") {
     web_contents()->GetMainFrame()->ExecuteJavaScriptForTests(
         base::ASCIIToUTF16("DevToolsAPI.setUseSoftMenu(true);"));
   } else if (method == "loadNetworkResource" && params->GetSize() == 3) {
     // TODO(pfeldman): handle some of the embedder messages in content.
     std::string url;
     std::string headers;
     int stream_id;
     if (!params->GetString(0, &url) || !params->GetString(1, &headers) ||
         !params->GetInteger(2, &stream_id)) {
       return;
     }

     GURL gurl(url);
     if (!gurl.is_valid()) {
       base::DictionaryValue response;
       response.SetInteger("statusCode", 404);
       SendMessageAck(request_id, &response);
       return;
     }

     net::NetworkTrafficAnnotationTag traffic_annotation =
         net::DefineNetworkTrafficAnnotation(
             "devtools_handle_front_end_messages", R"(
             semantics {
               sender: "Developer Tools"
               description:
                 "When user opens Developer Tools, the browser may fetch "
                 "additional resources from the network to enrich the debugging "
                 "experience (e.g. source map resources)."
               trigger: "User opens Developer Tools to debug a web page."
               data: "Any resources requested by Developer Tools."
               destination: OTHER
             }
             policy {
               cookies_allowed: YES
               cookies_store: "user"
               setting:
                 "It's not possible to disable this feature from settings."
               chrome_policy {
                 DeveloperToolsDisabled {
                   policy_options {mode: MANDATORY}
                   DeveloperToolsDisabled: true
                 }
               }
             })");
     net::URLFetcher* fetcher =
         net::URLFetcher::Create(gurl, net::URLFetcher::GET, this,
                                 traffic_annotation)
             .release();
     pending_requests_[fetcher] = request_id;
     fetcher->SetRequestContext(BrowserContext::GetDefaultStoragePartition(
                                    web_contents()->GetBrowserContext())
                                    ->GetURLRequestContext());
     fetcher->SetExtraRequestHeaders(headers);
     fetcher->SaveResponseWithWriter(
         std::unique_ptr<net::URLFetcherResponseWriter>(
             new ResponseWriter(weak_factory_.GetWeakPtr(), stream_id)));
     fetcher->Start();
     return;
   } else if (method == "getPreferences") {
     SendMessageAck(request_id, &preferences_);
     return;
   } else if (method == "setPreference") {
     std::string name;
     std::string value;
     if (!params->GetString(0, &name) || !params->GetString(1, &value)) {
       return;
     }
     preferences_.SetKey(name, base::Value(value));
   } else if (method == "removePreference") {
     std::string name;
     if (!params->GetString(0, &name))
       return;
     preferences_.RemoveWithoutPathExpansion(name, nullptr);
   } else if (method == "requestFileSystems") {
     web_contents()->GetMainFrame()->ExecuteJavaScriptForTests(
         base::ASCIIToUTF16("DevToolsAPI.fileSystemsLoaded([]);"));
   } else if (method == "reattach") {
     if (!agent_host_)
       return;
     agent_host_->DetachClient(this);
     agent_host_->AttachClient(this);
   } else if (method == "registerExtensionsAPI") {
     std::string origin;
     std::string script;
     if (!params->GetString(0, &origin) || !params->GetString(1, &script))
       return;
     extensions_api_[origin + "/"] = script;
   } else {
     return;
   }

   if (request_id)
     SendMessageAck(request_id, nullptr);
 }

 void ShellDevToolsBindings::DispatchProtocolMessage(
     DevToolsAgentHost* agent_host,
     const std::string& message) {
   if (message.length() < kMaxMessageChunkSize) {
     std::string param;
     base::EscapeJSONString(message, true, &param);
     std::string code = "DevToolsAPI.dispatchMessage(" + param + ");";
     base::string16 javascript = base::UTF8ToUTF16(code);
     web_contents()->GetMainFrame()->ExecuteJavaScriptForTests(javascript);
     return;
   }

   size_t total_size = message.length();
   for (size_t pos = 0; pos < message.length(); pos += kMaxMessageChunkSize) {
     std::string param;
     base::EscapeJSONString(message.substr(pos, kMaxMessageChunkSize), true,
                            &param);
     std::string code = "DevToolsAPI.dispatchMessageChunk(" + param + "," +
                        std::to_string(pos ? 0 : total_size) + ");";
     base::string16 javascript = base::UTF8ToUTF16(code);
     web_contents()->GetMainFrame()->ExecuteJavaScriptForTests(javascript);
   }
 }

 void ShellDevToolsBindings::OnURLFetchComplete(const net::URLFetcher* source) {
   // TODO(pfeldman): this is a copy of chrome's devtools_ui_bindings.cc.
   // We should handle some of the commands including this one in content.
   DCHECK(source);
   PendingRequestsMap::iterator it = pending_requests_.find(source);
   DCHECK(it != pending_requests_.end());

   base::DictionaryValue response;
   auto headers = std::make_unique<base::DictionaryValue>();
   net::HttpResponseHeaders* rh = source->GetResponseHeaders();
   response.SetInteger("statusCode", rh ? rh->response_code() : 200);

   size_t iterator = 0;
   std::string name;
   std::string value;
   while (rh && rh->EnumerateHeaderLines(&iterator, &name, &value))
     headers->SetString(name, value);
   response.Set("headers", std::move(headers));

   SendMessageAck(it->second, &response);
   pending_requests_.erase(it);
   delete source;
 }

 void ShellDevToolsBindings::CallClientFunction(const std::string& function_name,
                                                const base::Value* arg1,
                                                const base::Value* arg2,
                                                const base::Value* arg3) {
   std::string javascript = function_name + "(";
   if (arg1) {
     std::string json;
     base::JSONWriter::Write(*arg1, &json);
     javascript.append(json);
     if (arg2) {
       base::JSONWriter::Write(*arg2, &json);
       javascript.append(", ").append(json);
       if (arg3) {
         base::JSONWriter::Write(*arg3, &json);
         javascript.append(", ").append(json);
       }
     }
   }
   javascript.append(");");
   web_contents()->GetMainFrame()->ExecuteJavaScriptForTests(
       base::UTF8ToUTF16(javascript));
 }

 void ShellDevToolsBindings::SendMessageAck(int request_id,
                                            const base::Value* arg) {
   base::Value id_value(request_id);
   CallClientFunction("DevToolsAPI.embedderMessageAck", &id_value, arg, nullptr);
 }

 void ShellDevToolsBindings::AgentHostClosed(DevToolsAgentHost* agent_host) {
   agent_host_ = nullptr;
   if (delegate_)
     delegate_->Close();
 }

 }  // namespace content
	// Copyright 2017 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.

	#include "content/shell/browser/shell_devtools_bindings.h"

	#include <stddef.h>

	#include <utility>

	#include "base/guid.h"
	#include "base/json/json_reader.h"
	#include "base/json/json_writer.h"
	#include "base/json/string_escape.h"
	#include "base/macros.h"
	#include "base/memory/ptr_util.h"
	#include "base/strings/string_number_conversions.h"
	#include "base/strings/stringprintf.h"
	#include "base/strings/utf_string_conversions.h"
	#include "base/values.h"
	#include "content/public/browser/browser_thread.h"
	#include "content/public/browser/navigation_handle.h"
	#include "content/public/browser/render_frame_host.h"
	#include "content/public/browser/render_view_host.h"
	#include "content/public/browser/storage_partition.h"
	#include "content/public/browser/web_contents.h"
	#include "content/public/common/content_client.h"
	#include "content/shell/browser/shell.h"
	#include "content/shell/browser/shell_browser_context.h"
	#include "content/shell/browser/shell_browser_main_parts.h"
	#include "content/shell/browser/shell_content_browser_client.h"
	#include "content/shell/browser/shell_devtools_manager_delegate.h"
	#include "net/base/io_buffer.h"
	#include "net/base/net_errors.h"
	#include "net/http/http_response_headers.h"
	#include "net/traffic_annotation/network_traffic_annotation.h"
	#include "net/url_request/url_fetcher.h"
	#include "net/url_request/url_fetcher_response_writer.h"

	#if !defined(OS_ANDROID)
	#include "content/public/browser/devtools_frontend_host.h"
	#endif

	namespace content {

	namespace {

	// ResponseWriter -------------------------------------------------------------

	class ResponseWriter : public net::URLFetcherResponseWriter {
	public:
	ResponseWriter(base::WeakPtr<ShellDevToolsBindings> devtools_bindings_,
	int stream_id);
	~ResponseWriter() override;

	// URLFetcherResponseWriter overrides:
	int Initialize(const net::CompletionCallback& callback) override;
	int Write(net::IOBuffer* buffer,
	int num_bytes,
	const net::CompletionCallback& callback) override;
	int Finish(int net_error, const net::CompletionCallback& callback) override;

	private:
	base::WeakPtr<ShellDevToolsBindings> devtools_bindings_;
	int stream_id_;

	DISALLOW_COPY_AND_ASSIGN(ResponseWriter);
	};

	ResponseWriter::ResponseWriter(
	base::WeakPtr<ShellDevToolsBindings> shell_devtools,
	int stream_id)
	: devtools_bindings_(shell_devtools), stream_id_(stream_id) {}

	ResponseWriter::~ResponseWriter() {}

	int ResponseWriter::Initialize(const net::CompletionCallback& callback) {
	return net::OK;
	}

	int ResponseWriter::Write(net::IOBuffer* buffer,
	int num_bytes,
	const net::CompletionCallback& callback) {
	std::string chunk = std::string(buffer->data(), num_bytes);
	if (!base::IsStringUTF8(chunk))
	return num_bytes;

	base::Value* id = new base::Value(stream_id_);
	base::Value* chunkValue = new base::Value(chunk);

	content::BrowserThread::PostTask(
	content::BrowserThread::UI, FROM_HERE,
	base::BindOnce(&ShellDevToolsBindings::CallClientFunction,
	devtools_bindings_, "DevToolsAPI.streamWrite",
	base::Owned(id), base::Owned(chunkValue), nullptr));
	return num_bytes;
	}

	int ResponseWriter::Finish(int net_error,
	const net::CompletionCallback& callback) {
	return net::OK;
	}

	} // namespace

	// This constant should be in sync with
	// the constant at devtools_ui_bindings.cc.
	const size_t kMaxMessageChunkSize = IPC::Channel::kMaximumMessageSize / 4;

	void ShellDevToolsBindings::InspectElementAt(int x, int y) {
	if (agent_host_) {
	agent_host_->InspectElement(this, x, y);
	} else {
	inspect_element_at_x_ = x;
	inspect_element_at_y_ = y;
	}
	}

	ShellDevToolsBindings::ShellDevToolsBindings(WebContents* devtools_contents,
	WebContents* inspected_contents,
	ShellDevToolsDelegate* delegate)
	: WebContentsObserver(devtools_contents),
	inspected_contents_(inspected_contents),
	delegate_(delegate),
	inspect_element_at_x_(-1),
	inspect_element_at_y_(-1),
	weak_factory_(this) {}

	ShellDevToolsBindings::~ShellDevToolsBindings() {
	for (const auto& pair : pending_requests_)
	delete pair.first;
	if (agent_host_)
	agent_host_->DetachClient(this);
	}

	void ShellDevToolsBindings::ReadyToCommitNavigation(
	NavigationHandle* navigation_handle) {
	#if !defined(OS_ANDROID)
	content::RenderFrameHost* frame = navigation_handle->GetRenderFrameHost();
	if (navigation_handle->IsInMainFrame()) {
	frontend_host_.reset(DevToolsFrontendHost::Create(
	frame,
	base::Bind(&ShellDevToolsBindings::HandleMessageFromDevToolsFrontend,
	base::Unretained(this))));
	return;
	}
	std::string origin = navigation_handle->GetURL().GetOrigin().spec();
	auto it = extensions_api_.find(origin);
	if (it == extensions_api_.end())
	return;
	std::string script = base::StringPrintf("%s(\"%s\")", it->second.c_str(),
	base::GenerateGUID().c_str());
	DevToolsFrontendHost::SetupExtensionsAPI(frame, script);
	#endif
	}

	void ShellDevToolsBindings::Attach() {
	if (agent_host_)
	agent_host_->DetachClient(this);
	agent_host_ = DevToolsAgentHost::GetOrCreateFor(inspected_contents_);
	agent_host_->AttachClient(this);
	if (inspect_element_at_x_ != -1) {
	agent_host_->InspectElement(this, inspect_element_at_x_,
	inspect_element_at_y_);
	inspect_element_at_x_ = -1;
	inspect_element_at_y_ = -1;
	}
	}

	void ShellDevToolsBindings::WebContentsDestroyed() {
	if (agent_host_) {
	agent_host_->DetachClient(this);
	agent_host_ = nullptr;
	}
	}

	void ShellDevToolsBindings::HandleMessageFromDevToolsFrontend(
	const std::string& message) {
	std::string method;
	base::ListValue* params = nullptr;
	base::DictionaryValue* dict = nullptr;
	std::unique_ptr<base::Value> parsed_message = base::JSONReader::Read(message);
	if (!parsed_message \|\| !parsed_message->GetAsDictionary(&dict) \|\|
	!dict->GetString("method", &method)) {
	return;
	}
	int request_id = 0;
	dict->GetInteger("id", &request_id);
	dict->GetList("params", &params);

	if (method == "dispatchProtocolMessage" && params && params->GetSize() == 1) {
	std::string protocol_message;
	if (!agent_host_ \|\| !params->GetString(0, &protocol_message))
	return;
	agent_host_->DispatchProtocolMessage(this, protocol_message);
	} else if (method == "loadCompleted") {
	web_contents()->GetMainFrame()->ExecuteJavaScriptForTests(
	base::ASCIIToUTF16("DevToolsAPI.setUseSoftMenu(true);"));
	} else if (method == "loadNetworkResource" && params->GetSize() == 3) {
	// TODO(pfeldman): handle some of the embedder messages in content.
	std::string url;
	std::string headers;
	int stream_id;
	if (!params->GetString(0, &url) \|\| !params->GetString(1, &headers) \|\|
	!params->GetInteger(2, &stream_id)) {
	return;
	}

	GURL gurl(url);
	if (!gurl.is_valid()) {
	base::DictionaryValue response;
	response.SetInteger("statusCode", 404);
	SendMessageAck(request_id, &response);
	return;
	}

	net::NetworkTrafficAnnotationTag traffic_annotation =
	net::DefineNetworkTrafficAnnotation(
	"devtools_handle_front_end_messages", R"(
	semantics {
	sender: "Developer Tools"
	description:
	"When user opens Developer Tools, the browser may fetch "
	"additional resources from the network to enrich the debugging "
	"experience (e.g. source map resources)."
	trigger: "User opens Developer Tools to debug a web page."
	data: "Any resources requested by Developer Tools."
	destination: OTHER
	}
	policy {
	cookies_allowed: YES
	cookies_store: "user"
	setting:
	"It's not possible to disable this feature from settings."
	chrome_policy {
	DeveloperToolsDisabled {
	policy_options {mode: MANDATORY}
	DeveloperToolsDisabled: true
	}
	}
	})");
	net::URLFetcher* fetcher =
	net::URLFetcher::Create(gurl, net::URLFetcher::GET, this,
	traffic_annotation)
	.release();
	pending_requests_[fetcher] = request_id;
	fetcher->SetRequestContext(BrowserContext::GetDefaultStoragePartition(
	web_contents()->GetBrowserContext())
	->GetURLRequestContext());
	fetcher->SetExtraRequestHeaders(headers);
	fetcher->SaveResponseWithWriter(
	std::unique_ptr<net::URLFetcherResponseWriter>(
	new ResponseWriter(weak_factory_.GetWeakPtr(), stream_id)));
	fetcher->Start();
	return;
	} else if (method == "getPreferences") {
	SendMessageAck(request_id, &preferences_);
	return;
	} else if (method == "setPreference") {
	std::string name;
	std::string value;
	if (!params->GetString(0, &name) \|\| !params->GetString(1, &value)) {
	return;
	}
	preferences_.SetKey(name, base::Value(value));
	} else if (method == "removePreference") {
	std::string name;
	if (!params->GetString(0, &name))
	return;
	preferences_.RemoveWithoutPathExpansion(name, nullptr);
	} else if (method == "requestFileSystems") {
	web_contents()->GetMainFrame()->ExecuteJavaScriptForTests(
	base::ASCIIToUTF16("DevToolsAPI.fileSystemsLoaded([]);"));
	} else if (method == "reattach") {
	if (!agent_host_)
	return;
	agent_host_->DetachClient(this);
	agent_host_->AttachClient(this);
	} else if (method == "registerExtensionsAPI") {
	std::string origin;
	std::string script;
	if (!params->GetString(0, &origin) \|\| !params->GetString(1, &script))
	return;
	extensions_api_[origin + "/"] = script;
	} else {
	return;
	}

	if (request_id)
	SendMessageAck(request_id, nullptr);
	}

	void ShellDevToolsBindings::DispatchProtocolMessage(
	DevToolsAgentHost* agent_host,
	const std::string& message) {
	if (message.length() < kMaxMessageChunkSize) {
	std::string param;
	base::EscapeJSONString(message, true, &param);
	std::string code = "DevToolsAPI.dispatchMessage(" + param + ");";
	base::string16 javascript = base::UTF8ToUTF16(code);
	web_contents()->GetMainFrame()->ExecuteJavaScriptForTests(javascript);
	return;
	}

	size_t total_size = message.length();
	for (size_t pos = 0; pos < message.length(); pos += kMaxMessageChunkSize) {
	std::string param;
	base::EscapeJSONString(message.substr(pos, kMaxMessageChunkSize), true,
	&param);
	std::string code = "DevToolsAPI.dispatchMessageChunk(" + param + "," +
	std::to_string(pos ? 0 : total_size) + ");";
	base::string16 javascript = base::UTF8ToUTF16(code);
	web_contents()->GetMainFrame()->ExecuteJavaScriptForTests(javascript);
	}
	}

	void ShellDevToolsBindings::OnURLFetchComplete(const net::URLFetcher* source) {
	// TODO(pfeldman): this is a copy of chrome's devtools_ui_bindings.cc.
	// We should handle some of the commands including this one in content.
	DCHECK(source);
	PendingRequestsMap::iterator it = pending_requests_.find(source);
	DCHECK(it != pending_requests_.end());

	base::DictionaryValue response;
	auto headers = std::make_unique<base::DictionaryValue>();
	net::HttpResponseHeaders* rh = source->GetResponseHeaders();
	response.SetInteger("statusCode", rh ? rh->response_code() : 200);

	size_t iterator = 0;
	std::string name;
	std::string value;
	while (rh && rh->EnumerateHeaderLines(&iterator, &name, &value))
	headers->SetString(name, value);
	response.Set("headers", std::move(headers));

	SendMessageAck(it->second, &response);
	pending_requests_.erase(it);
	delete source;
	}

	void ShellDevToolsBindings::CallClientFunction(const std::string& function_name,
	const base::Value* arg1,
	const base::Value* arg2,
	const base::Value* arg3) {
	std::string javascript = function_name + "(";
	if (arg1) {
	std::string json;
	base::JSONWriter::Write(*arg1, &json);
	javascript.append(json);
	if (arg2) {
	base::JSONWriter::Write(*arg2, &json);
	javascript.append(", ").append(json);
	if (arg3) {
	base::JSONWriter::Write(*arg3, &json);
	javascript.append(", ").append(json);
	}
	}
	}
	javascript.append(");");
	web_contents()->GetMainFrame()->ExecuteJavaScriptForTests(
	base::UTF8ToUTF16(javascript));
	}

	void ShellDevToolsBindings::SendMessageAck(int request_id,
	const base::Value* arg) {
	base::Value id_value(request_id);
	CallClientFunction("DevToolsAPI.embedderMessageAck", &id_value, arg, nullptr);
	}

	void ShellDevToolsBindings::AgentHostClosed(DevToolsAgentHost* agent_host) {
	agent_host_ = nullptr;
	if (delegate_)
	delegate_->Close();
	}

	} // namespace content