Do not give GPU memory to backgrounded compositors.

cc/output/managed_memory_policy.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_OUTPUT_MANAGED_MEMORY_POLICY_H_
 #define CC_OUTPUT_MANAGED_MEMORY_POLICY_H_
 
 #include "base/basictypes.h"
 #include "cc/base/cc_export.h"
 #include "cc/resources/tile_priority.h"
 #include "gpu/command_buffer/common/gpu_memory_allocation.h"
 
 namespace cc {
 
 struct CC_EXPORT ManagedMemoryPolicy {
   static const size_t kDefaultNumResourcesLimit;
 
   explicit ManagedMemoryPolicy(size_t bytes_limit_when_visible);
   explicit ManagedMemoryPolicy(
       const gpu::MemoryAllocation& allocation);
   ManagedMemoryPolicy(
       size_t bytes_limit_when_visible,
       gpu::MemoryAllocation::PriorityCutoff priority_cutoff_when_visible,
-      size_t bytes_limit_when_not_visible,
-      gpu::MemoryAllocation::PriorityCutoff priority_cutoff_when_not_visible,
       size_t num_resources_limit);
   bool operator==(const ManagedMemoryPolicy&) const;
   bool operator!=(const ManagedMemoryPolicy&) const;
 
   size_t bytes_limit_when_visible;
   gpu::MemoryAllocation::PriorityCutoff priority_cutoff_when_visible;
-  size_t bytes_limit_when_not_visible;
-  gpu::MemoryAllocation::PriorityCutoff priority_cutoff_when_not_visible;
   size_t num_resources_limit;
 
   static int PriorityCutoffToValue(
       gpu::MemoryAllocation::PriorityCutoff priority_cutoff);
   static TileMemoryLimitPolicy PriorityCutoffToTileMemoryLimitPolicy(
       gpu::MemoryAllocation::PriorityCutoff priority_cutoff);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_MANAGED_MEMORY_POLICY_H_