Add calls to inform gpu of browser window count

content/public/browser/gpu_data_manager.h

Index: content/public/browser/gpu_data_manager.h
diff --git a/content/public/browser/gpu_data_manager.h b/content/public/browser/gpu_data_manager.h
index 3a61e23f798bc0c5ad80661566ffdd83b7cc25ab..8bcea35b0533dd707566da30ee0e1f9e2ba66d40 100644
--- a/content/public/browser/gpu_data_manager.h
+++ b/content/public/browser/gpu_data_manager.h
@@ -79,6 +79,11 @@ class GpuDataManager {
   virtual void AddObserver(GpuDataManagerObserver* observer) = 0;
   virtual void RemoveObserver(GpuDataManagerObserver* observer) = 0;
 
+  // Notifies the gpu process about the number of browser windows, so
+  // they can be used to determine managed memory allocation.
+  virtual void SetWindowCount(uint32 count) = 0;
+  virtual uint32 GetWindowCount() const = 0;
+
  protected:
   virtual ~GpuDataManager() {}
 };