GpuScheduler using time quantum to avoid too many PostTasks

gpu/command_buffer/service/gpu_scheduler.h

Index: gpu/command_buffer/service/gpu_scheduler.h
diff --git a/gpu/command_buffer/service/gpu_scheduler.h b/gpu/command_buffer/service/gpu_scheduler.h
index d75beae081f455e526dfb0ac94070ec05ec52505..b49713f0381c43690a268a0f42d0ec09a96b77ce 100644
--- a/gpu/command_buffer/service/gpu_scheduler.h
+++ b/gpu/command_buffer/service/gpu_scheduler.h
@@ -39,6 +39,10 @@ class ContextGroup;
 // posts tasks to the current message loop to do additional work.
 class GpuScheduler : public CommandBufferEngine {
  public:
+  // Scheduler quantum: makes ProcessCommands continue until the specified time
+  // has passed, or the command buffer yields or runs out of commands.
+  static const int kMinimumSchedulerQuantumMicros = 2000;
+
   // If a group is not passed in one will be created.
   GpuScheduler(CommandBuffer* command_buffer,
                SurfaceManager* surface_manager,