blob: 0d6ee685da95b258b8f3f04c3d497aa4ac3e2e1e [file] [log] [blame]
// 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.
#include "content/browser/renderer_host/compositor_impl_android.h"
#include <android/bitmap.h>
#include <android/native_window_jni.h>
#include "base/android/jni_android.h"
#include "base/android/scoped_java_ref.h"
#include "base/bind.h"
#include "base/command_line.h"
#include "base/containers/hash_tables.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/memory/weak_ptr.h"
#include "base/single_thread_task_runner.h"
#include "base/synchronization/lock.h"
#include "base/threading/thread.h"
#include "base/threading/thread_checker.h"
#include "cc/base/switches.h"
#include "cc/input/input_handler.h"
#include "cc/layers/layer.h"
#include "cc/output/compositor_frame.h"
#include "cc/output/context_provider.h"
#include "cc/output/output_surface.h"
#include "cc/trees/layer_tree_host.h"
#include "content/browser/android/child_process_launcher_android.h"
#include "content/browser/gpu/browser_gpu_channel_host_factory.h"
#include "content/browser/gpu/gpu_surface_tracker.h"
#include "content/common/gpu/client/command_buffer_proxy_impl.h"
#include "content/common/gpu/client/context_provider_command_buffer.h"
#include "content/common/gpu/client/gl_helper.h"
#include "content/common/gpu/client/gpu_channel_host.h"
#include "content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h"
#include "content/common/gpu/gpu_process_launch_causes.h"
#include "content/common/host_shared_bitmap_manager.h"
#include "content/public/browser/android/compositor_client.h"
#include "gpu/command_buffer/client/gles2_interface.h"
#include "third_party/khronos/GLES2/gl2.h"
#include "third_party/khronos/GLES2/gl2ext.h"
#include "third_party/skia/include/core/SkMallocPixelRef.h"
#include "ui/base/android/window_android.h"
#include "ui/gfx/android/device_display_info.h"
#include "ui/gfx/frame_time.h"
#include "ui/gl/android/surface_texture.h"
#include "ui/gl/android/surface_texture_tracker.h"
#include "webkit/common/gpu/context_provider_in_process.h"
#include "webkit/common/gpu/webgraphicscontext3d_in_process_command_buffer_impl.h"
namespace {
const unsigned int kMaxSwapBuffers = 2U;
// Used to override capabilities_.adjust_deadline_for_parent to false
class OutputSurfaceWithoutParent : public cc::OutputSurface {
public:
OutputSurfaceWithoutParent(const scoped_refptr<
content::ContextProviderCommandBuffer>& context_provider,
base::WeakPtr<content::CompositorImpl> compositor_impl)
: cc::OutputSurface(context_provider) {
capabilities_.adjust_deadline_for_parent = false;
compositor_impl_ = compositor_impl;
main_thread_ = base::MessageLoopProxy::current();
}
virtual void SwapBuffers(cc::CompositorFrame* frame) OVERRIDE {
for (size_t i = 0; i < frame->metadata.latency_info.size(); i++) {
frame->metadata.latency_info[i].AddLatencyNumber(
ui::INPUT_EVENT_BROWSER_SWAP_BUFFER_COMPONENT, 0, 0);
}
content::ContextProviderCommandBuffer* provider_command_buffer =
static_cast<content::ContextProviderCommandBuffer*>(
context_provider_.get());
content::CommandBufferProxyImpl* command_buffer_proxy =
provider_command_buffer->GetCommandBufferProxy();
DCHECK(command_buffer_proxy);
command_buffer_proxy->SetLatencyInfo(frame->metadata.latency_info);
OutputSurface::SwapBuffers(frame);
}
virtual bool BindToClient(cc::OutputSurfaceClient* client) OVERRIDE {
if (!OutputSurface::BindToClient(client))
return false;
main_thread_->PostTask(
FROM_HERE,
base::Bind(&content::CompositorImpl::PopulateGpuCapabilities,
compositor_impl_,
context_provider_->ContextCapabilities().gpu));
return true;
}
scoped_refptr<base::MessageLoopProxy> main_thread_;
base::WeakPtr<content::CompositorImpl> compositor_impl_;
};
class SurfaceTextureTrackerImpl : public gfx::SurfaceTextureTracker {
public:
SurfaceTextureTrackerImpl() : next_surface_texture_id_(1) {
thread_checker_.DetachFromThread();
}
// Overridden from gfx::SurfaceTextureTracker:
virtual scoped_refptr<gfx::SurfaceTexture> AcquireSurfaceTexture(
int primary_id,
int secondary_id) OVERRIDE {
base::AutoLock lock(surface_textures_lock_);
SurfaceTextureMapKey key(primary_id, secondary_id);
SurfaceTextureMap::iterator it = surface_textures_.find(key);
if (it == surface_textures_.end())
return scoped_refptr<gfx::SurfaceTexture>();
scoped_refptr<gfx::SurfaceTexture> surface_texture = it->second;
surface_textures_.erase(it);
return surface_texture;
}
int AddSurfaceTexture(gfx::SurfaceTexture* surface_texture,
int child_process_id) {
DCHECK(thread_checker_.CalledOnValidThread());
int surface_texture_id = next_surface_texture_id_++;
if (next_surface_texture_id_ == INT_MAX)
next_surface_texture_id_ = 1;
base::AutoLock lock(surface_textures_lock_);
SurfaceTextureMapKey key(surface_texture_id, child_process_id);
DCHECK(surface_textures_.find(key) == surface_textures_.end());
surface_textures_[key] = surface_texture;
content::RegisterChildProcessSurfaceTexture(
surface_texture_id,
child_process_id,
surface_texture->j_surface_texture().obj());
return surface_texture_id;
}
void RemoveAllSurfaceTextures(int child_process_id) {
DCHECK(thread_checker_.CalledOnValidThread());
base::AutoLock lock(surface_textures_lock_);
SurfaceTextureMap::iterator it = surface_textures_.begin();
while (it != surface_textures_.end()) {
if (it->first.second == child_process_id) {
content::UnregisterChildProcessSurfaceTexture(it->first.first,
it->first.second);
surface_textures_.erase(it++);
} else {
++it;
}
}
}
private:
typedef std::pair<int, int> SurfaceTextureMapKey;
typedef base::hash_map<SurfaceTextureMapKey,
scoped_refptr<gfx::SurfaceTexture> >
SurfaceTextureMap;
SurfaceTextureMap surface_textures_;
mutable base::Lock surface_textures_lock_;
int next_surface_texture_id_;
base::ThreadChecker thread_checker_;
};
base::LazyInstance<SurfaceTextureTrackerImpl> g_surface_texture_tracker =
LAZY_INSTANCE_INITIALIZER;
static bool g_initialized = false;
} // anonymous namespace
namespace content {
// static
Compositor* Compositor::Create(CompositorClient* client,
gfx::NativeWindow root_window) {
return client ? new CompositorImpl(client, root_window) : NULL;
}
// static
void Compositor::Initialize() {
DCHECK(!CompositorImpl::IsInitialized());
// SurfaceTextureTracker instance must be set before we create a GPU thread
// that could be using it to initialize GLImage instances.
gfx::SurfaceTextureTracker::InitInstance(g_surface_texture_tracker.Pointer());
g_initialized = true;
}
// static
bool CompositorImpl::IsInitialized() {
return g_initialized;
}
// static
int CompositorImpl::CreateSurfaceTexture(int child_process_id) {
// Note: this needs to be 0 as the surface texture implemenation will take
// ownership of the texture and call glDeleteTextures when the GPU service
// attaches the surface texture to a real texture id. glDeleteTextures
// silently ignores 0.
const int kDummyTextureId = 0;
scoped_refptr<gfx::SurfaceTexture> surface_texture =
gfx::SurfaceTexture::Create(kDummyTextureId);
return g_surface_texture_tracker.Pointer()->AddSurfaceTexture(
surface_texture.get(), child_process_id);
}
// static
void CompositorImpl::DestroyAllSurfaceTextures(int child_process_id) {
g_surface_texture_tracker.Pointer()->RemoveAllSurfaceTextures(
child_process_id);
}
CompositorImpl::CompositorImpl(CompositorClient* client,
gfx::NativeWindow root_window)
: root_layer_(cc::Layer::Create()),
has_transparent_background_(false),
device_scale_factor_(1),
window_(NULL),
surface_id_(0),
client_(client),
root_window_(root_window),
did_post_swapbuffers_(false),
ignore_schedule_composite_(false),
needs_composite_(false),
needs_animate_(false),
will_composite_immediately_(false),
composite_on_vsync_trigger_(DO_NOT_COMPOSITE),
pending_swapbuffers_(0U),
weak_factory_(this) {
DCHECK(client);
DCHECK(root_window);
ImageTransportFactoryAndroid::AddObserver(this);
root_window->AttachCompositor(this);
}
CompositorImpl::~CompositorImpl() {
root_window_->DetachCompositor();
ImageTransportFactoryAndroid::RemoveObserver(this);
// Clean-up any surface references.
SetSurface(NULL);
}
void CompositorImpl::PostComposite(CompositingTrigger trigger) {
DCHECK(needs_composite_);
DCHECK(trigger == COMPOSITE_IMMEDIATELY || trigger == COMPOSITE_EVENTUALLY);
if (will_composite_immediately_ ||
(trigger == COMPOSITE_EVENTUALLY && WillComposite())) {
// We will already composite soon enough.
DCHECK(WillComposite());
return;
}
if (DidCompositeThisFrame()) {
DCHECK(!WillCompositeThisFrame());
if (composite_on_vsync_trigger_ != COMPOSITE_IMMEDIATELY) {
composite_on_vsync_trigger_ = trigger;
root_window_->RequestVSyncUpdate();
}
DCHECK(WillComposite());
return;
}
base::TimeDelta delay;
if (trigger == COMPOSITE_IMMEDIATELY) {
will_composite_immediately_ = true;
composite_on_vsync_trigger_ = DO_NOT_COMPOSITE;
} else {
DCHECK(!WillComposite());
const base::TimeDelta estimated_composite_time = vsync_period_ / 4;
const base::TimeTicks now = base::TimeTicks::Now();
if (!last_vsync_.is_null() && (now - last_vsync_) < vsync_period_) {
base::TimeTicks next_composite =
last_vsync_ + vsync_period_ - estimated_composite_time;
if (next_composite < now) {
// It's too late, we will reschedule composite as needed on the next
// vsync.
composite_on_vsync_trigger_ = COMPOSITE_EVENTUALLY;
root_window_->RequestVSyncUpdate();
DCHECK(WillComposite());
return;
}
delay = next_composite - now;
}
}
TRACE_EVENT2("cc", "CompositorImpl::PostComposite",
"trigger", trigger,
"delay", delay.InMillisecondsF());
DCHECK(composite_on_vsync_trigger_ == DO_NOT_COMPOSITE);
if (current_composite_task_)
current_composite_task_->Cancel();
// Unretained because we cancel the task on shutdown.
current_composite_task_.reset(new base::CancelableClosure(
base::Bind(&CompositorImpl::Composite, base::Unretained(this), trigger)));
base::MessageLoop::current()->PostDelayedTask(
FROM_HERE, current_composite_task_->callback(), delay);
}
void CompositorImpl::Composite(CompositingTrigger trigger) {
BrowserGpuChannelHostFactory* factory =
BrowserGpuChannelHostFactory::instance();
if (!factory->GetGpuChannel() || factory->GetGpuChannel()->IsLost()) {
CauseForGpuLaunch cause =
CAUSE_FOR_GPU_LAUNCH_WEBGRAPHICSCONTEXT3DCOMMANDBUFFERIMPL_INITIALIZE;
factory->EstablishGpuChannel(cause,
base::Bind(&CompositorImpl::ScheduleComposite,
weak_factory_.GetWeakPtr()));
return;
}
DCHECK(host_);
DCHECK(trigger == COMPOSITE_IMMEDIATELY || trigger == COMPOSITE_EVENTUALLY);
DCHECK(needs_composite_);
DCHECK(!DidCompositeThisFrame());
if (trigger == COMPOSITE_IMMEDIATELY)
will_composite_immediately_ = false;
DCHECK_LE(pending_swapbuffers_, kMaxSwapBuffers);
if (pending_swapbuffers_ == kMaxSwapBuffers) {
TRACE_EVENT0("compositor", "CompositorImpl_SwapLimit");
return;
}
// Reset state before Layout+Composite since that might create more
// requests to Composite that we need to respect.
needs_composite_ = false;
// Only allow compositing once per vsync.
current_composite_task_->Cancel();
DCHECK(DidCompositeThisFrame() && !WillComposite());
// Ignore ScheduleComposite() from layer tree changes during layout and
// animation updates that will already be reflected in the current frame
// we are about to draw.
ignore_schedule_composite_ = true;
const base::TimeTicks frame_time = gfx::FrameTime::Now();
if (needs_animate_) {
needs_animate_ = false;
root_window_->Animate(frame_time);
}
ignore_schedule_composite_ = false;
did_post_swapbuffers_ = false;
host_->Composite(frame_time);
if (did_post_swapbuffers_)
pending_swapbuffers_++;
// Need to track vsync to avoid compositing more than once per frame.
root_window_->RequestVSyncUpdate();
}
UIResourceProvider& CompositorImpl::GetUIResourceProvider() {
return ui_resource_provider_;
}
ui::SystemUIResourceManager& CompositorImpl::GetSystemUIResourceManager() {
return ui_resource_provider_.GetSystemUIResourceManager();
}
void CompositorImpl::SetRootLayer(scoped_refptr<cc::Layer> root_layer) {
if (subroot_layer_.get()) {
subroot_layer_->RemoveFromParent();
subroot_layer_ = NULL;
}
if (root_layer.get()) {
subroot_layer_ = root_layer;
root_layer_->AddChild(root_layer);
}
}
void CompositorImpl::SetWindowSurface(ANativeWindow* window) {
GpuSurfaceTracker* tracker = GpuSurfaceTracker::Get();
if (window_) {
tracker->RemoveSurface(surface_id_);
ANativeWindow_release(window_);
window_ = NULL;
surface_id_ = 0;
SetVisible(false);
}
if (window) {
window_ = window;
ANativeWindow_acquire(window);
surface_id_ = tracker->AddSurfaceForNativeWidget(window);
tracker->SetSurfaceHandle(
surface_id_,
gfx::GLSurfaceHandle(gfx::kNullPluginWindow, gfx::NATIVE_DIRECT));
SetVisible(true);
}
}
void CompositorImpl::SetSurface(jobject surface) {
JNIEnv* env = base::android::AttachCurrentThread();
base::android::ScopedJavaLocalRef<jobject> j_surface(env, surface);
// First, cleanup any existing surface references.
if (surface_id_)
content::UnregisterViewSurface(surface_id_);
SetWindowSurface(NULL);
// Now, set the new surface if we have one.
ANativeWindow* window = NULL;
if (surface) {
// Note: This ensures that any local references used by
// ANativeWindow_fromSurface are released immediately. This is needed as a
// workaround for https://code.google.com/p/android/issues/detail?id=68174
base::android::ScopedJavaLocalFrame scoped_local_reference_frame(env);
window = ANativeWindow_fromSurface(env, surface);
}
if (window) {
SetWindowSurface(window);
ANativeWindow_release(window);
content::RegisterViewSurface(surface_id_, j_surface.obj());
}
}
void CompositorImpl::SetVisible(bool visible) {
if (!visible) {
DCHECK(host_);
// Look for any layers that were attached to the root for readback
// and are waiting for Composite() to happen.
bool readback_pending = false;
for (size_t i = 0; i < root_layer_->children().size(); ++i) {
if (root_layer_->children()[i]->HasCopyRequest()) {
readback_pending = true;
break;
}
}
if (readback_pending) {
ignore_schedule_composite_ = true;
host_->Composite(base::TimeTicks::Now());
ignore_schedule_composite_ = false;
}
if (WillComposite())
CancelComposite();
ui_resource_provider_.SetLayerTreeHost(NULL);
host_.reset();
} else if (!host_) {
DCHECK(!WillComposite());
needs_composite_ = false;
pending_swapbuffers_ = 0;
cc::LayerTreeSettings settings;
settings.refresh_rate = 60.0;
settings.impl_side_painting = false;
settings.allow_antialiasing = false;
settings.calculate_top_controls_position = false;
settings.top_controls_height = 0.f;
settings.highp_threshold_min = 2048;
base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
settings.initial_debug_state.SetRecordRenderingStats(
command_line->HasSwitch(cc::switches::kEnableGpuBenchmarking));
settings.initial_debug_state.show_fps_counter =
command_line->HasSwitch(cc::switches::kUIShowFPSCounter);
// TODO(enne): Update this this compositor to use the scheduler.
settings.single_thread_proxy_scheduler = false;
host_ = cc::LayerTreeHost::CreateSingleThreaded(
this,
this,
HostSharedBitmapManager::current(),
settings,
base::MessageLoopProxy::current());
host_->SetRootLayer(root_layer_);
host_->SetVisible(true);
host_->SetLayerTreeHostClientReady();
host_->SetViewportSize(size_);
host_->set_has_transparent_background(has_transparent_background_);
host_->SetDeviceScaleFactor(device_scale_factor_);
ui_resource_provider_.SetLayerTreeHost(host_.get());
}
}
void CompositorImpl::setDeviceScaleFactor(float factor) {
device_scale_factor_ = factor;
if (host_)
host_->SetDeviceScaleFactor(factor);
}
void CompositorImpl::SetWindowBounds(const gfx::Size& size) {
if (size_ == size)
return;
size_ = size;
if (host_)
host_->SetViewportSize(size);
root_layer_->SetBounds(size);
}
void CompositorImpl::SetHasTransparentBackground(bool flag) {
has_transparent_background_ = flag;
if (host_)
host_->set_has_transparent_background(flag);
}
void CompositorImpl::SetNeedsComposite() {
if (!host_.get())
return;
DCHECK(!needs_composite_ || WillComposite());
needs_composite_ = true;
PostComposite(COMPOSITE_IMMEDIATELY);
}
static scoped_ptr<WebGraphicsContext3DCommandBufferImpl>
CreateGpuProcessViewContext(
const scoped_refptr<GpuChannelHost>& gpu_channel_host,
const blink::WebGraphicsContext3D::Attributes attributes,
int surface_id) {
DCHECK(gpu_channel_host.get());
GURL url("chrome://gpu/Compositor::createContext3D");
static const size_t kBytesPerPixel = 4;
gfx::DeviceDisplayInfo display_info;
size_t full_screen_texture_size_in_bytes =
display_info.GetDisplayHeight() *
display_info.GetDisplayWidth() *
kBytesPerPixel;
WebGraphicsContext3DCommandBufferImpl::SharedMemoryLimits limits;
limits.command_buffer_size = 64 * 1024;
limits.start_transfer_buffer_size = 64 * 1024;
limits.min_transfer_buffer_size = 64 * 1024;
limits.max_transfer_buffer_size = std::min(
3 * full_screen_texture_size_in_bytes, kDefaultMaxTransferBufferSize);
limits.mapped_memory_reclaim_limit = 2 * 1024 * 1024;
bool lose_context_when_out_of_memory = true;
return make_scoped_ptr(
new WebGraphicsContext3DCommandBufferImpl(surface_id,
url,
gpu_channel_host.get(),
attributes,
lose_context_when_out_of_memory,
limits,
NULL));
}
void CompositorImpl::Layout() {
ignore_schedule_composite_ = true;
client_->Layout();
ignore_schedule_composite_ = false;
}
void CompositorImpl::RequestNewOutputSurface(bool fallback) {
BrowserGpuChannelHostFactory* factory =
BrowserGpuChannelHostFactory::instance();
if (!factory->GetGpuChannel() || factory->GetGpuChannel()->IsLost()) {
CauseForGpuLaunch cause =
CAUSE_FOR_GPU_LAUNCH_WEBGRAPHICSCONTEXT3DCOMMANDBUFFERIMPL_INITIALIZE;
factory->EstablishGpuChannel(
cause,
base::Bind(&CompositorImpl::CreateOutputSurface,
weak_factory_.GetWeakPtr(),
fallback));
return;
}
CreateOutputSurface(fallback);
}
void CompositorImpl::CreateOutputSurface(bool fallback) {
blink::WebGraphicsContext3D::Attributes attrs;
attrs.shareResources = true;
attrs.noAutomaticFlushes = true;
pending_swapbuffers_ = 0;
DCHECK(window_);
DCHECK(surface_id_);
scoped_refptr<ContextProviderCommandBuffer> context_provider;
BrowserGpuChannelHostFactory* factory =
BrowserGpuChannelHostFactory::instance();
scoped_refptr<GpuChannelHost> gpu_channel_host = factory->GetGpuChannel();
if (gpu_channel_host.get() && !gpu_channel_host->IsLost()) {
context_provider = ContextProviderCommandBuffer::Create(
CreateGpuProcessViewContext(gpu_channel_host, attrs, surface_id_),
"BrowserCompositor");
}
if (!context_provider.get()) {
LOG(ERROR) << "Failed to create 3D context for compositor.";
host_->SetOutputSurface(scoped_ptr<cc::OutputSurface>());
return;
}
host_->SetOutputSurface(
scoped_ptr<cc::OutputSurface>(new OutputSurfaceWithoutParent(
context_provider, weak_factory_.GetWeakPtr())));
}
void CompositorImpl::PopulateGpuCapabilities(
gpu::Capabilities gpu_capabilities) {
ui_resource_provider_.SetSupportsETC1NonPowerOfTwo(
gpu_capabilities.texture_format_etc1_npot);
}
void CompositorImpl::OnLostResources() {
client_->DidLoseResources();
}
void CompositorImpl::ScheduleComposite() {
DCHECK(!needs_composite_ || WillComposite());
if (ignore_schedule_composite_)
return;
needs_composite_ = true;
// We currently expect layer tree invalidations at most once per frame
// during normal operation and therefore try to composite immediately
// to minimize latency.
PostComposite(COMPOSITE_IMMEDIATELY);
}
void CompositorImpl::ScheduleAnimation() {
DCHECK(!needs_composite_ || WillComposite());
needs_animate_ = true;
if (needs_composite_)
return;
TRACE_EVENT0("cc", "CompositorImpl::ScheduleAnimation");
needs_composite_ = true;
PostComposite(COMPOSITE_EVENTUALLY);
}
void CompositorImpl::DidPostSwapBuffers() {
TRACE_EVENT0("compositor", "CompositorImpl::DidPostSwapBuffers");
did_post_swapbuffers_ = true;
}
void CompositorImpl::DidCompleteSwapBuffers() {
TRACE_EVENT0("compositor", "CompositorImpl::DidCompleteSwapBuffers");
DCHECK_GT(pending_swapbuffers_, 0U);
if (pending_swapbuffers_-- == kMaxSwapBuffers && needs_composite_)
PostComposite(COMPOSITE_IMMEDIATELY);
client_->OnSwapBuffersCompleted(pending_swapbuffers_);
}
void CompositorImpl::DidAbortSwapBuffers() {
TRACE_EVENT0("compositor", "CompositorImpl::DidAbortSwapBuffers");
// This really gets called only once from
// SingleThreadProxy::DidLoseOutputSurfaceOnImplThread() when the
// context was lost.
ScheduleComposite();
client_->OnSwapBuffersCompleted(0);
}
void CompositorImpl::DidCommit() {
root_window_->OnCompositingDidCommit();
}
void CompositorImpl::AttachLayerForReadback(scoped_refptr<cc::Layer> layer) {
root_layer_->AddChild(layer);
}
void CompositorImpl::RequestCopyOfOutputOnRootLayer(
scoped_ptr<cc::CopyOutputRequest> request) {
root_layer_->RequestCopyOfOutput(request.Pass());
}
void CompositorImpl::OnVSync(base::TimeTicks frame_time,
base::TimeDelta vsync_period) {
vsync_period_ = vsync_period;
last_vsync_ = frame_time;
if (WillCompositeThisFrame()) {
// We somehow missed the last vsync interval, so reschedule for deadline.
// We cannot schedule immediately, or will get us out-of-phase with new
// renderer frames.
CancelComposite();
composite_on_vsync_trigger_ = COMPOSITE_EVENTUALLY;
} else {
current_composite_task_.reset();
}
DCHECK(!DidCompositeThisFrame() && !WillCompositeThisFrame());
if (composite_on_vsync_trigger_ != DO_NOT_COMPOSITE) {
CompositingTrigger trigger = composite_on_vsync_trigger_;
composite_on_vsync_trigger_ = DO_NOT_COMPOSITE;
PostComposite(trigger);
}
}
void CompositorImpl::SetNeedsAnimate() {
if (!host_)
return;
host_->SetNeedsAnimate();
}
} // namespace content