Do not give GPU memory to backgrounded compositors.

cc/debug/test_context_provider.h

 // Copyright 2013 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 CC_DEBUG_TEST_CONTEXT_PROVIDER_H_
 #define CC_DEBUG_TEST_CONTEXT_PROVIDER_H_
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
@@ skipping 31 matching lines @@
       const MemoryPolicyChangedCallback& cb) OVERRIDE;
 
   TestWebGraphicsContext3D* TestContext3d();
 
   // This returns the TestWebGraphicsContext3D but is valid to call
   // before the context is bound to a thread. This is needed to set up
   // state on the test context before binding. Don't call
   // makeContextCurrent on the context returned from this method.
   TestWebGraphicsContext3D* UnboundTestContext3d();
 
-  void SetMemoryAllocation(const ManagedMemoryPolicy& policy,
-                           bool discard_backbuffer_when_not_visible);
+  void SetMemoryAllocation(const ManagedMemoryPolicy& policy);
 
   void SetMaxTransferBufferUsageBytes(size_t max_transfer_buffer_usage_bytes);
 
  protected:
   TestContextProvider(scoped_ptr<TestWebGraphicsContext3D> context);
   virtual ~TestContextProvider();
 
   void OnLostContext();
   void OnSwapBuffersComplete();
 
@@ skipping 17 matching lines @@
 
   class SwapBuffersCompleteCallbackProxy;
   scoped_ptr<SwapBuffersCompleteCallbackProxy>
       swap_buffers_complete_callback_proxy_;
 };
 
 }  // namespace cc
 
 #endif  // CC_DEBUG_TEST_CONTEXT_PROVIDER_H_