Add DrawingBuffer multisample resolve unit test.

third_party/WebKit/Source/platform/graphics/gpu/DrawingBufferSoftwareRenderingTest.cpp

 // Copyright 2016 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 "platform/graphics/gpu/DrawingBuffer.h"
 
 #include "cc/resources/single_release_callback.h"
 #include "cc/resources/texture_mailbox.h"
 #include "gpu/command_buffer/client/gles2_interface_stub.h"
 #include "platform/graphics/gpu/DrawingBufferTestHelpers.h"
@@ skipping 36 matching lines @@
  protected:
   void SetUp() override {
     IntSize initial_size(kInitialWidth, kInitialHeight);
     std::unique_ptr<GLES2InterfaceForTests> gl =
         WTF::WrapUnique(new GLES2InterfaceForTests);
     std::unique_ptr<WebGraphicsContext3DProviderSoftwareRenderingForTests>
         provider = WTF::WrapUnique(
             new WebGraphicsContext3DProviderSoftwareRenderingForTests(
                 std::move(gl)));
     drawing_buffer_ = DrawingBufferForTests::Create(
-        std::move(provider), nullptr, initial_size, DrawingBuffer::kPreserve);
+        std::move(provider), nullptr, initial_size, DrawingBuffer::kPreserve,
+        kDisableMultisampling);
     CHECK(drawing_buffer_);
   }
 
   RefPtr<DrawingBufferForTests> drawing_buffer_;
   bool is_software_rendering_ = false;
 };
 
 TEST_F(DrawingBufferSoftwareRenderingTest, bitmapRecycling) {
   cc::TextureMailbox texture_mailbox;
   std::unique_ptr<cc::SingleReleaseCallback> release_callback1;
@@ skipping 27 matching lines @@
       &release_callback3);  // cause recycling queue to be purged due to resize
   EXPECT_EQ(0, drawing_buffer_->RecycledBitmapCount());
   release_callback3->Run(gpu::SyncToken(), false /* lostResource */);
   EXPECT_EQ(1, drawing_buffer_->RecycledBitmapCount());
 
   drawing_buffer_->BeginDestruction();
 }
 
 }  // unnamed namespace
 }  // blink