Send idle notifications to V8 after commit

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 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/renderer/gpu/render_widget_compositor.h"
 
 #include <limits>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 20 matching lines @@
 #include "content/common/content_switches_internal.h"
 #include "content/common/gpu/client/context_provider_command_buffer.h"
 #include "content/public/common/content_switches.h"
 #include "content/renderer/compositor_bindings/web_layer_impl.h"
 #include "content/renderer/input/input_handler_manager.h"
 #include "content/renderer/render_thread_impl.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "third_party/WebKit/public/platform/WebCompositeAndReadbackAsyncCallback.h"
 #include "third_party/WebKit/public/platform/WebSelectionBound.h"
 #include "third_party/WebKit/public/platform/WebSize.h"
+#include "third_party/WebKit/public/web/WebKit.h"
 #include "third_party/WebKit/public/web/WebWidget.h"
 #include "ui/gfx/frame_time.h"
 #include "ui/gl/gl_switches.h"
 #include "ui/native_theme/native_theme_switches.h"
 
 #if defined(OS_ANDROID)
 #include "content/renderer/android/synchronous_compositor_factory.h"
 #include "ui/gfx/android/device_display_info.h"
 #endif
 
@@ skipping 115 matching lines @@
   cc::LayerTreeSettings settings;
 
   // For web contents, layer transforms should scale up the contents of layers
   // to keep content always crisp when possible.
   settings.layer_transforms_should_scale_layer_contents = true;
 
   settings.throttle_frame_production =
       !cmd->HasSwitch(switches::kDisableGpuVsync);
   settings.begin_frame_scheduling_enabled =
       cmd->HasSwitch(switches::kEnableBeginFrameScheduling);
+  settings.send_v8_idle_notification_after_commit =

[jamesr, 2014/08/18 23:23:49]

you're setting this here in content/renderer/...

+      cmd->HasSwitch(cc::switches::kSendV8IdleNotificationAfterCommit);
   settings.main_frame_before_activation_enabled =
       cmd->HasSwitch(cc::switches::kEnableMainFrameBeforeActivation) &&
       !cmd->HasSwitch(cc::switches::kDisableMainFrameBeforeActivation);
   settings.main_frame_before_draw_enabled =
       !cmd->HasSwitch(cc::switches::kDisableMainFrameBeforeDraw);
   settings.report_overscroll_only_for_scrollable_axes = true;
   settings.accelerated_animation_enabled =
       !cmd->HasSwitch(cc::switches::kDisableThreadedAnimation);
 
   settings.default_tile_size = CalculateDefaultTileSize();
@@ skipping 564 matching lines @@
 void RenderWidgetCompositor::WillBeginMainFrame(int frame_id) {
   widget_->InstrumentWillBeginFrame(frame_id);
   widget_->willBeginCompositorFrame();
 }
 
 void RenderWidgetCompositor::DidBeginMainFrame() {
   widget_->InstrumentDidBeginFrame();
 }
 
 void RenderWidgetCompositor::BeginMainFrame(const cc::BeginFrameArgs& args) {
+  begin_main_frame_args_ = args;
   double frame_time = (args.frame_time - base::TimeTicks()).InSecondsF();
   WebBeginFrameArgs web_begin_frame_args = WebBeginFrameArgs(frame_time);
   widget_->webwidget()->beginFrame(web_begin_frame_args);
 }
 
 void RenderWidgetCompositor::Layout() {
   widget_->webwidget()->layout();
 }
 
 void RenderWidgetCompositor::ApplyScrollAndScale(
     const gfx::Vector2d& scroll_delta,
     float page_scale) {
   widget_->webwidget()->applyScrollAndScale(scroll_delta, page_scale);
 }
 
 scoped_ptr<cc::OutputSurface> RenderWidgetCompositor::CreateOutputSurface(
     bool fallback) {
   return widget_->CreateOutputSurface(fallback);
 }
 
 void RenderWidgetCompositor::DidInitializeOutputSurface() {
 }
 
 void RenderWidgetCompositor::WillCommit() {
   widget_->InstrumentWillComposite();
 }
 
 void RenderWidgetCompositor::DidCommit() {
+  int idle_time_for_gc =
+      std::max(0L, (begin_main_frame_args_.frame_time +
+                    begin_main_frame_args_.interval -
+                    base::TimeTicks::HighResNow()).InMilliseconds());
+  if (layer_tree_host_->settings().send_v8_idle_notification_after_commit &&

[jamesr, 2014/08/18 23:23:49]

... and then querying it again here, in the same object. there's no need to
involve the cc:: settings object at all. just store a bool or query the flag
status again here

[ernstm, 2014/08/18 23:46:34]

Done.

+      idle_time_for_gc)
+    blink::mainThreadIsolate()->IdleNotification(idle_time_for_gc);
+
   widget_->DidCommitCompositorFrame();
   widget_->didBecomeReadyForAdditionalInput();
 }
 
 void RenderWidgetCompositor::DidCommitAndDrawFrame() {
   widget_->didCommitAndDrawCompositorFrame();
 }
 
 void RenderWidgetCompositor::DidCompleteSwapBuffers() {
   widget_->didCompleteSwapBuffers();
@@ skipping 18 matching lines @@
   widget_->OnSwapBuffersAborted();
 }
 
 void RenderWidgetCompositor::RateLimitSharedMainThreadContext() {
   cc::ContextProvider* provider =
       RenderThreadImpl::current()->SharedMainThreadContextProvider().get();
   provider->ContextGL()->RateLimitOffscreenContextCHROMIUM();
 }
 
 }  // namespace content