Schedule idle timer of render thread when user is idle.

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 962e8569b21753acf8a39184c9bd3d7779656184..cb4c109c755da9f4561faf5bda244e6551fbcdb5 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -560,21 +560,30 @@ void RenderThreadImpl::ScheduleIdleHandler(double initial_delay_s) {
 void RenderThreadImpl::IdleHandler() {
   #if !defined(OS_MACOSX) && defined(USE_TCMALLOC)
   MallocExtension::instance()->ReleaseFreeMemory();
-#endif
-
-  v8::V8::IdleNotification();
+  #endif
 
-  // Schedule next invocation.
-  // Dampen the delay using the algorithm:
-  //    delay = delay + 1 / (delay + 2)
-  // Using floor(delay) has a dampening effect such as:
-  //    1s, 1, 1, 2, 2, 2, 2, 3, 3, ...
-  // Note that idle_notification_delay_in_s_ would be reset to
-  // kInitialIdleHandlerDelayS in RenderThreadImpl::WidgetHidden.
-  ScheduleIdleHandler(idle_notification_delay_in_s_ +
-                      1.0 / (idle_notification_delay_in_s_ + 2.0));
-
-  FOR_EACH_OBSERVER(RenderProcessObserver, observers_, IdleNotification());
+  if (hidden_widget_count_ < widget_count_ &&
+      content::GetContentClient()->renderer()->RunIdleHandlerWhenUserIdle()) {
+    if (!v8::V8::IdleNotification()) {
+      ScheduleIdleHandler(kInitialIdleHandlerDelayS);
+    } else {
+      idle_timer_.Stop();
+    }
+  } else {
+    v8::V8::IdleNotification();
+
+    // Schedule next invocation.
+    // Dampen the delay using the algorithm:
+    //    delay = delay + 1 / (delay + 2)
+    // Using floor(delay) has a dampening effect such as:
+    //    1s, 1, 1, 2, 2, 2, 2, 3, 3, ...
+    // Note that idle_notification_delay_in_s_ would be reset to
+    // kInitialIdleHandlerDelayS in RenderThreadImpl::WidgetHidden.
+    ScheduleIdleHandler(idle_notification_delay_in_s_ +
+                        1.0 / (idle_notification_delay_in_s_ + 2.0));
+
+    FOR_EACH_OBSERVER(RenderProcessObserver, observers_, IdleNotification());
+  }
 }
 
 double RenderThreadImpl::GetIdleNotificationDelayInS() const {
@@ -789,3 +798,4 @@ RenderThreadImpl::GetFileThreadMessageLoopProxy() {
   }
   return file_thread_->message_loop_proxy();
 }
+