Plumb cc::LatencyInfo through command buffer and output surface

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 512012d0e690d5a554cb745aa32cbe4cb2421632..a51a9fcbc4373d00b7924908393b2537b5c0c143 100644
--- a/content/common/gpu/gpu_command_buffer_stub.h
+++ b/content/common/gpu/gpu_command_buffer_stub.h
@@ -12,6 +12,7 @@
 #include "base/id_map.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
+#include "cc/debug/latency_info.h"
 #include "content/common/content_export.h"
 #include "content/common/gpu/gpu_memory_allocation.h"
 #include "content/common/gpu/gpu_memory_manager.h"
@@ -58,6 +59,9 @@ class GpuCommandBufferStub
     virtual ~DestructionObserver() {}
   };
 
+  typedef base::Callback<void(const cc::LatencyInfo&)>
+      LatencyInfoCallback;
+
   GpuCommandBufferStub(
       GpuChannel* channel,
       GpuCommandBufferStub* share_group,
@@ -130,6 +134,8 @@ class GpuCommandBufferStub
 
   void SetPreemptByFlag(scoped_refptr<gpu::PreemptionFlag> flag);
 
+  void SetLatencyInfoCallback(const LatencyInfoCallback& callback);
+
  private:
   GpuMemoryManager* GetMemoryManager();
   bool MakeCurrent();
@@ -177,6 +183,7 @@ class GpuCommandBufferStub
 
   void OnCommandProcessed();
   void OnParseError();
+  void OnSetLatencyInfo(const cc::LatencyInfo& latency_info);
 
   void ReportState();
 
@@ -244,6 +251,8 @@ class GpuCommandBufferStub
 
   scoped_refptr<gpu::PreemptionFlag> preemption_flag_;
 
+  LatencyInfoCallback latency_info_callback_;
+
   GURL active_url_;
   size_t active_url_hash_;