cc: Make OutputSurfaceFrame::sub_buffer_rect optional

cc/test/fake_output_surface.cc

 // Copyright 2012 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/fake_output_surface.h"
 
 #include "base/bind.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "cc/output/output_surface_client.h"
 #include "cc/resources/returned_resource.h"
@@ skipping 27 matching lines @@
   } else {
     software_device()->Resize(size, device_scale_factor);
   }
   last_reshape_color_space_ = color_space;
 }
 
 void FakeOutputSurface::SwapBuffers(OutputSurfaceFrame frame) {
   last_sent_frame_.reset(new OutputSurfaceFrame(std::move(frame)));
   ++num_sent_frames_;
 
-  if (context_provider()) {
-    last_swap_rect_ = last_sent_frame_->sub_buffer_rect;
-    last_swap_rect_valid_ = true;
-  } else {
-    // Unknown for direct software frames.
-    last_swap_rect_ = gfx::Rect();
-    last_swap_rect_valid_ = false;
-  }
-
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(&FakeOutputSurface::SwapBuffersAck,
                             weak_ptr_factory_.GetWeakPtr()));
 }
 
 void FakeOutputSurface::SwapBuffersAck() {
   client_->DidReceiveSwapBuffersAck();
 }
 
 void FakeOutputSurface::BindFramebuffer() {
@@ skipping 28 matching lines @@
 
 bool FakeOutputSurface::IsDisplayedAsOverlayPlane() const {
   return false;
 }
 
 unsigned FakeOutputSurface::GetOverlayTextureId() const {
   return 0;
 }
 
 }  // namespace cc