Add a command-line flag to set GPU rasterization multisampling.

content/test/fake_compositor_dependencies.cc

 // Copyright 2014 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/test/fake_compositor_dependencies.h"
 
 #include "base/message_loop/message_loop_proxy.h"
 #include "cc/test/fake_external_begin_frame_source.h"
 #include "third_party/khronos/GLES2/gl2.h"
 
 namespace content {
 
 FakeCompositorDependencies::FakeCompositorDependencies() {
 }
 
 bool FakeCompositorDependencies::IsImplSidePaintingEnabled() {
   return true;
 }
 
 bool FakeCompositorDependencies::IsGpuRasterizationForced() {
   return false;
 }
 
 bool FakeCompositorDependencies::IsGpuRasterizationEnabled() {
   return false;
 }
 
+int FakeCompositorDependencies::GpuRasterizationMSAASampleCount() {
+  return 0;
+}
+
 bool FakeCompositorDependencies::IsLcdTextEnabled() {
   return false;
 }
 
 bool FakeCompositorDependencies::IsDistanceFieldTextEnabled() {
   return false;
 }
 
 bool FakeCompositorDependencies::IsZeroCopyEnabled() {
   return false;
@@ skipping 40 matching lines @@
   return nullptr;
 }
 
 scoped_ptr<cc::BeginFrameSource>
 FakeCompositorDependencies::CreateExternalBeginFrameSource(int routing_id) {
   double refresh_rate = 200.0;
   return make_scoped_ptr(new cc::FakeExternalBeginFrameSource(refresh_rate));
 }
 
 }  // namespace content