Fix and re-enable v8 idle notification 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 405 matching lines @@
 
   compositor->Initialize(settings);
 
   return compositor.Pass();
 }
 
 RenderWidgetCompositor::RenderWidgetCompositor(RenderWidget* widget,
                                                bool threaded)
     : threaded_(threaded),
       widget_(widget),
-      send_v8_idle_notification_after_commit_(false) {
+      send_v8_idle_notification_after_commit_(true) {
   CommandLine* cmd = CommandLine::ForCurrentProcess();
 
   if (cmd->HasSwitch(switches::kEnableV8IdleNotificationAfterCommit))
     send_v8_idle_notification_after_commit_ = true;
   if (cmd->HasSwitch(switches::kDisableV8IdleNotificationAfterCommit))
     send_v8_idle_notification_after_commit_ = false;
 }
 
 RenderWidgetCompositor::~RenderWidgetCompositor() {}
 
@@ skipping 373 matching lines @@
 
 void RenderWidgetCompositor::DidCommit() {
   if (send_v8_idle_notification_after_commit_) {
     base::TimeDelta idle_time = begin_main_frame_time_ +
                                 begin_main_frame_interval_ -
                                 gfx::FrameTime::Now();
     if (idle_time > base::TimeDelta()) {
       // Convert to 32-bit microseconds first to avoid costly 64-bit division.
       int32 idle_time_in_us = idle_time.InMicroseconds();
       int32 idle_time_in_ms = idle_time_in_us / 1000;
-      blink::mainThreadIsolate()->IdleNotification(idle_time_in_ms);
+      if (idle_time_in_ms)
+        blink::mainThreadIsolate()->IdleNotification(idle_time_in_ms);
     }
   }
 
   widget_->DidCommitCompositorFrame();
   widget_->didBecomeReadyForAdditionalInput();
   widget_->webwidget()->didCommitFrameToCompositor();
 }
 
 void RenderWidgetCompositor::DidCommitAndDrawFrame() {
   widget_->didCommitAndDrawCompositorFrame();
@@ skipping 17 matching lines @@
   widget_->OnSwapBuffersAborted();
 }
 
 void RenderWidgetCompositor::RateLimitSharedMainThreadContext() {
   cc::ContextProvider* provider =
       RenderThreadImpl::current()->SharedMainThreadContextProvider().get();
   provider->ContextGL()->RateLimitOffscreenContextCHROMIUM();
 }
 
 }  // namespace content