Add compile flag for enabling the compostior

sky/viewer/platform/weblayertreeview_impl.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 "sky/viewer/platform/weblayertreeview_impl.h"
 
 #include "base/message_loop/message_loop_proxy.h"
 #include "cc/layers/layer.h"
 #include "cc/output/begin_frame_args.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/trees/layer_tree_host.h"
 #include "mojo/cc/context_provider_mojo.h"
 #include "mojo/cc/output_surface_mojo.h"
 #include "mojo/converters/surfaces/surfaces_type_converters.h"
 #include "mojo/services/public/cpp/view_manager/view.h"
+#include "sky/engine/public/web/WebSettings.h"
+#include "sky/engine/public/web/WebView.h"
 #include "sky/engine/public/web/WebWidget.h"
 #include "sky/viewer/cc/web_layer_impl.h"
+#include "third_party/skia/include/core/SkCanvas.h"
 
 namespace sky {
 
 WebLayerTreeViewImpl::WebLayerTreeViewImpl(
     scoped_refptr<base::MessageLoopProxy> compositor_message_loop_proxy,
     mojo::SurfacesServicePtr surfaces_service,
     mojo::GpuPtr gpu_service)
     : widget_(NULL),
       view_(NULL),
       surfaces_service_(surfaces_service.Pass()),
@@ skipping 22 matching lines @@
                                         base::MessageLoopProxy::current(),
                                         compositor_message_loop_proxy,
                                         nullptr);
   DCHECK(layer_tree_host_);
 }
 
 WebLayerTreeViewImpl::~WebLayerTreeViewImpl() {
   layer_tree_host_.reset();
 }
 
+void WebLayerTreeViewImpl::PaintContents(SkCanvas* canvas,
+                                         const gfx::Rect& clip,
+                                         GraphicsContextStatus gc_status) {
+  blink::WebRect rect(clip.x(), clip.y(), clip.width(), clip.height());
+  widget_->paint(canvas, rect);
+  canvas->flush();
+}
+
+bool WebLayerTreeViewImpl::FillsBoundsCompletely() const {
+  // TODO(abarth): We should be able to return true when we're opaque.
+  return false;
+}
+
 void WebLayerTreeViewImpl::WillBeginMainFrame(int frame_id) {
 }
 
 void WebLayerTreeViewImpl::DidBeginMainFrame() {
 }
 
 void WebLayerTreeViewImpl::BeginMainFrame(const cc::BeginFrameArgs& args) {
   VLOG(2) << "WebLayerTreeViewImpl::BeginMainFrame";
   double frame_time_sec = (args.frame_time - base::TimeTicks()).InSecondsF();
   double deadline_sec = (args.deadline - base::TimeTicks()).InSecondsF();
   double interval_sec = args.interval.InSecondsF();
   blink::WebBeginFrameArgs web_begin_frame_args(
       frame_time_sec, deadline_sec, interval_sec);
   widget_->beginFrame(web_begin_frame_args);
 }
 
+void WebLayerTreeViewImpl::set_widget(blink::WebWidget* widget) {
+  widget_ = widget;
+
+  // TODO(sky): The only reason this is here is because we need the widget to
+  // check whether the compositor is enabled.
+  if (!static_cast<blink::WebView*>(widget_)->settings()->compositorIsEnabled()) {
+    root_layer_ = cc::ContentLayer::Create(this);
+    layer_tree_host_->SetRootLayer(root_layer_);
+  }
+}
+
 void WebLayerTreeViewImpl::Layout() {
   widget_->layout();
+  blink::WebSize size = widget_->size();
+
+  if (!static_cast<blink::WebView*>(widget_)->settings()->compositorIsEnabled()) {
+    root_layer_->SetBounds(gfx::Size(size.width, size.height));
+    root_layer_->SetIsDrawable(true);
+    root_layer_->SetNeedsDisplay();
+  }
 }
 
 void WebLayerTreeViewImpl::ApplyViewportDeltas(
     const gfx::Vector2d& scroll_delta,
     float page_scale,
     float top_controls_delta) {
 }
 
 void WebLayerTreeViewImpl::ApplyViewportDeltas(const gfx::Vector2d& inner_delta,
                                                const gfx::Vector2d& outer_delta,
@@ skipping 123 matching lines @@
       base::Bind(&WebLayerTreeViewImpl::DidCreateSurfaceOnMainThread,
                  main_thread_bound_weak_ptr_,
                  id));
 }
 
 void WebLayerTreeViewImpl::DidCreateSurfaceOnMainThread(cc::SurfaceId id) {
   view_->SetSurfaceId(mojo::SurfaceId::From(id));
 }
 
 }  // namespace sky