Reland 179911 and 179910

content/common/gpu/gpu_command_buffer_stub.h

Index: content/common/gpu/gpu_command_buffer_stub.h
diff --git a/content/common/gpu/gpu_command_buffer_stub.h b/content/common/gpu/gpu_command_buffer_stub.h
index 0519e8c7fd0f30e967e4d8cdc68f5c7d04c4207e..886aca9bf0bcb3b04ccb259076df7904367e36a0 100644
--- a/content/common/gpu/gpu_command_buffer_stub.h
+++ b/content/common/gpu/gpu_command_buffer_stub.h
@@ -97,6 +97,11 @@ class GpuCommandBufferStub
   // Whether this command buffer can currently handle IPC messages.
   bool IsScheduled();
 
+  // If the command buffer is pre-empted and cannot process commands.
+  bool IsPreempted() const {
+    return scheduler_.get() && scheduler_->IsPreempted();
+  }
+
   // Whether there are commands in the buffer that haven't been processed.
   bool HasUnprocessedCommands();
 
@@ -130,7 +135,7 @@ class GpuCommandBufferStub
   // retire all sync points that haven't been previously retired.
   void AddSyncPoint(uint32 sync_point);
 
-  void SetPreemptByCounter(scoped_refptr<gpu::RefCountedCounter> counter);
+  void SetPreemptByFlag(scoped_refptr<gpu::PreemptionFlag> flag);
 
  private:
   GpuMemoryManager* GetMemoryManager();
@@ -244,7 +249,7 @@ class GpuCommandBufferStub
 
   bool delayed_work_scheduled_;
 
-  scoped_refptr<gpu::RefCountedCounter> preempt_by_counter_;
+  scoped_refptr<gpu::PreemptionFlag> preemption_flag_;
 
   GURL active_url_;
   size_t active_url_hash_;