Add GPU memory tab to the task manager.

content/browser/gpu/gpu_data_manager_impl.h

Index: content/browser/gpu/gpu_data_manager_impl.h
diff --git a/content/browser/gpu/gpu_data_manager_impl.h b/content/browser/gpu/gpu_data_manager_impl.h
index c0ed419c4dfec33e20819262dada312efe5fb491..646acba63c06785729f4d1fa94a2fa14421509b4 100644
--- a/content/browser/gpu/gpu_data_manager_impl.h
+++ b/content/browser/gpu/gpu_data_manager_impl.h
@@ -33,6 +33,7 @@ class CONTENT_EXPORT GpuDataManagerImpl
   virtual bool GpuAccessAllowed() OVERRIDE;
   virtual void RequestCompleteGpuInfoIfNeeded() OVERRIDE;
   virtual bool IsCompleteGPUInfoAvailable() const OVERRIDE;
+  virtual void RequestVidmemUpdate() OVERRIDE;
   virtual bool ShouldUseSoftwareRendering() OVERRIDE;
   virtual void RegisterSwiftShaderPath(const FilePath& path) OVERRIDE;
   virtual const base::ListValue& GetLogMessages() const OVERRIDE;
@@ -43,6 +44,8 @@ class CONTENT_EXPORT GpuDataManagerImpl
   // Only update if the current GPUInfo is not finalized.
   void UpdateGpuInfo(const content::GPUInfo& gpu_info);
 
+  void UpdateVidmem(const content::GPUVidmem& vidmem);
+
   void AddLogMessage(Value* msg);
 
   // Insert disable-feature switches corresponding to preliminary gpu feature