Add very simple cc::Display implementation for surfaces.

cc/surfaces/display.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.
+
+#ifndef CC_SURFACES_DISPLAY_H_
+#define CC_SURFACES_DISPLAY_H_
+
+#include "cc/surfaces/display.h"
+
+#include "base/message_loop/message_loop.h"
+#include "cc/output/compositor_frame.h"
+#include "cc/output/direct_renderer.h"
+#include "cc/output/gl_renderer.h"
+#include "cc/surfaces/display_client.h"
+#include "cc/surfaces/surface.h"
+
+namespace cc {
+
+Display::Display(DisplayClient* client, SurfaceManager* manager)
+    : scheduled_draw_(false),
+      client_(client),
+      manager_(manager),
+      aggregator_(manager) {
+}
+
+Display::~Display() {
+}
+
+void Display::Resize(const gfx::Size& size) {
+  current_surface_.reset(new Surface(manager_, this, size));
+}
+
+bool Display::Draw() {
+  if (!current_surface_)
+    return false;
+
+  scoped_ptr<CompositorFrame> frame = current_surface_->TakeFrame();
+
+  if (!layer_tree_host_) {
+    LayerTreeSettings settings;
+    layer_tree_host_ =
+        LayerTreeHost::CreateSingleThreaded(this, this, NULL, settings);
+    resource_collection_ = new DelegatedFrameResourceCollection;
+    resource_collection_->SetClient(this);
+    layer_tree_host_->SetLayerTreeHostClientReady();
+  }
+  if (!delegated_frame_provider_ ||
+      delegated_frame_provider_->frame_size() !=
+          frame->delegated_frame_data->render_pass_list.back()
+              ->output_rect.size()) {
+    delegated_frame_provider_ = new DelegatedFrameProvider(
+        resource_collection_, frame->delegated_frame_data.Pass());
+    delegated_layer_ =
+        DelegatedRendererLayer::Create(delegated_frame_provider_);
+
+    layer_tree_host_->SetRootLayer(delegated_layer_);
+    delegated_layer_->SetDisplaySize(current_surface_->size());
+    delegated_layer_->SetBounds(current_surface_->size());
+    delegated_layer_->SetContentsOpaque(true);
+    delegated_layer_->SetIsDrawable(true);
+  } else {
+    delegated_frame_provider_->SetFrameData(frame->delegated_frame_data.Pass());
+  }
+  layer_tree_host_->SetViewportSize(current_surface_->size());
+
+  return true;
+}
+
+scoped_ptr<OutputSurface> Display::CreateOutputSurface(bool fallback) {
+  return client_->CreateOutputSurface();
+}
+
+void Display::ScheduleComposite() {
+  if (scheduled_draw_)
+    return;
+
+  scheduled_draw_ = true;
+
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE, base::Bind(&Display::DoComposite, base::Unretained(this)));
+}
+
+void Display::DoComposite() {
+  scheduled_draw_ = false;
+  layer_tree_host_->Composite(base::TimeTicks::Now());
+}
+
+int Display::CurrentSurfaceID() {
+  return current_surface_ ? current_surface_->surface_id() : 0;
+}
+
+void Display::ReturnResources(const ReturnedResourceArray& resources) {
+  // We never generate any resources, so we should never have any returned.
+  DCHECK(resources.empty());
+}
+
+}  // namespace cc
+
+#endif  // CC_SURFACES_DISPLAY_H_