Add GPU memory tab to the task manager.

chrome/browser/gpu_feature_checker.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_GPU_FEATURE_CHECKER_H_
 #define CHROME_BROWSER_GPU_FEATURE_CHECKER_H_
 
 #include "base/callback.h"
 #include "content/public/browser/gpu_data_manager_observer.h"
 #include "content/public/common/gpu_feature_type.h"
@@ skipping 11 matching lines @@
   GPUFeatureChecker(content::GpuFeatureType feature,
                     FeatureAvailableCallback callback);
 
   // Check to see if |feature_| is available on the current GPU. |callback_|
   // will be called to indicate the availability of the feature. Must be called
   // from the the UI thread.
   void CheckGPUFeatureAvailability();
 
   // content::GpuDataManagerObserver
   virtual void OnGpuInfoUpdate() OVERRIDE;
+  virtual void OnVideoMemoryUsageStatsUpdate(
+      const content::GPUVideoMemoryUsageStats& video_memory_usage_stats)
+          OVERRIDE {}
  private:
   friend class base::RefCountedThreadSafe<GPUFeatureChecker>;
 
   virtual ~GPUFeatureChecker();
 
   content::GpuFeatureType feature_;
   FeatureAvailableCallback callback_;
 
   DISALLOW_COPY_AND_ASSIGN(GPUFeatureChecker);
 };
 
 #endif  // CHROME_BROWSER_GPU_FEATURE_CHECKER_H_