Use a cc::Display for WebView resourceless software draws.

cc/output/compositor_frame_metadata.cc

 // Copyright (c) 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/output/compositor_frame_metadata.h"
 
 namespace cc {
 
-CompositorFrameMetadata::CompositorFrameMetadata()
-    : device_scale_factor(0.f),
-      page_scale_factor(0.f),
-      min_page_scale_factor(0.f),
-      max_page_scale_factor(0.f),
-      root_overflow_x_hidden(false),
-      root_overflow_y_hidden(false),
-      root_background_color(SK_ColorWHITE) {}
+CompositorFrameMetadata::CompositorFrameMetadata() = default;
 
 CompositorFrameMetadata::CompositorFrameMetadata(
     CompositorFrameMetadata&& other) = default;
 
 CompositorFrameMetadata::~CompositorFrameMetadata() {
 }
 
 CompositorFrameMetadata& CompositorFrameMetadata::operator=(
     CompositorFrameMetadata&& other) = default;
 
 CompositorFrameMetadata CompositorFrameMetadata::Clone() const {
   CompositorFrameMetadata metadata(*this);
   return metadata;
 }
 
 CompositorFrameMetadata::CompositorFrameMetadata(
     const CompositorFrameMetadata& other) = default;
 
 }  // namespace cc