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

cc/test/layer_tree_pixel_resource_test.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 "cc/test/layer_tree_pixel_resource_test.h"
 
 #include "cc/layers/layer.h"
 #include "cc/resources/bitmap_tile_task_worker_pool.h"
 #include "cc/resources/gpu_rasterizer.h"
 #include "cc/resources/gpu_tile_task_worker_pool.h"
@@ skipping 122 matching lines @@
   ResourceProvider* resource_provider = host_impl->resource_provider();
   switch (resource_pool_option_) {
     case BITMAP_TILE_TASK_WORKER_POOL:
     case ZERO_COPY_TILE_TASK_WORKER_POOL:
     case ONE_COPY_TILE_TASK_WORKER_POOL:
     case PIXEL_BUFFER_TILE_TASK_WORKER_POOL:
       return SoftwareRasterizer::Create();
     case GPU_TILE_TASK_WORKER_POOL:
       EXPECT_TRUE(context_provider);
       return GpuRasterizer::Create(context_provider, resource_provider,
-                                   use_distance_field_text, false);
+                                   use_distance_field_text, false, 0);
   }
   NOTREACHED();
   return nullptr;
 }
 
 void LayerTreeHostPixelResourceTest::CreateResourceAndTileTaskWorkerPool(
     LayerTreeHostImpl* host_impl,
     scoped_ptr<TileTaskWorkerPool>* tile_task_worker_pool,
     scoped_ptr<ResourcePool>* resource_pool,
     scoped_ptr<ResourcePool>* staging_resource_pool) {
@@ skipping 78 matching lines @@
 
   if (layer_tree_host())
     EXPECT_TRUE(layer_tree_host()->settings().impl_side_painting);
 }
 
 ParameterizedPixelResourceTest::ParameterizedPixelResourceTest()
     : LayerTreeHostPixelResourceTest(GetParam()) {
 }
 
 }  // namespace cc