Do not give GPU memory to backgrounded compositors.

content/common/gpu/client/context_provider_command_buffer.cc

 // Copyright (c) 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.
 
 #include "content/common/gpu/client/context_provider_command_buffer.h"
 
 #include <set>
 #include <vector>
 
 #include "base/callback_helpers.h"
@@ skipping 186 matching lines @@
   DCHECK(context_thread_checker_.CalledOnValidThread());
 
   if (gr_context_) {
     bool nonzero_allocation = !!allocation.bytes_limit_when_visible;
     gr_context_->SetMemoryLimit(nonzero_allocation);
   }
 
   if (memory_policy_changed_callback_.is_null())
     return;
 
-  bool discard_backbuffer_when_not_visible =
-      !allocation.have_backbuffer_when_not_visible;
-
-  memory_policy_changed_callback_.Run(
-      cc::ManagedMemoryPolicy(allocation), discard_backbuffer_when_not_visible);
+  memory_policy_changed_callback_.Run(cc::ManagedMemoryPolicy(allocation));
 }
 
 bool ContextProviderCommandBuffer::InitializeCapabilities() {
   // The command buffer provides the following capabilities always.
   // TODO(jamesr): This information is duplicated with
   // gpu::gles2::FeatureInfo::AddFeatures().
   Capabilities caps;
   caps.bind_uniform_location = true;
   caps.discard_backbuffer = true;
   caps.set_visibility = true;
@@ skipping 85 matching lines @@
 
 void ContextProviderCommandBuffer::SetMemoryPolicyChangedCallback(
     const MemoryPolicyChangedCallback& memory_policy_changed_callback) {
   DCHECK(context_thread_checker_.CalledOnValidThread());
   DCHECK(memory_policy_changed_callback_.is_null() ||
          memory_policy_changed_callback.is_null());
   memory_policy_changed_callback_ = memory_policy_changed_callback;
 }
 
 }  // namespace content