Enables compositing support for webview.

content/renderer/browser_plugin/browser_plugin_compositing_helper.cc

+// Copyright (c) 2013 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 "content/renderer/browser_plugin/browser_plugin_compositing_helper.h"
+
+#include "cc/texture_layer.h"
+#include "content/common/browser_plugin_messages.h"
+#include "content/renderer/render_thread_impl.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebPluginContainer.h"
+#include "webkit/compositor_bindings/web_layer_impl.h"
+
+namespace content {
+
+BrowserPluginCompositingHelper::BrowserPluginCompositingHelper(
+    WebKit::WebPluginContainer* container,
+    int host_routing_id)
+    : host_routing_id_(host_routing_id),
+      last_mailbox_valid_(false),
+      container_(container) {
+}
+
+void BrowserPluginCompositingHelper::EnableCompositing(bool enable) {
+  if (enable && !texture_layer_) {
+      texture_layer_ = cc::TextureLayer::createForMailbox();
+      web_layer_.reset(new WebKit::WebLayerImpl(texture_layer_));
+  }
+
+  container_->setWebLayer(enable ? web_layer_.get() : NULL);
+}
+
+BrowserPluginCompositingHelper::~BrowserPluginCompositingHelper() {
+  if (texture_layer_) {
+    texture_layer_->setTextureMailbox(std::string(),
+                                      cc::TextureLayer::MailboxCallback());

[piman, 2013/01/09 22:38:57]

Is this necessary given that you are about to delete texture_layer_ ?

[alexst (slow to review), 2013/01/09 23:16:05]

You are probably right. I was thinking that if the layer is still in the tree
for one more commit, it would speed up the ack on the last buffer, but it would
get ACK'd in the destructor anyway.

+  }

[piman, 2013/01/09 22:38:57]

you want to reset the container_'s weblayer here, otherwise it still references
a dangling pointer.

[alexst (slow to review), 2013/01/09 23:16:05]

Done.

[alexst (slow to review), 2013/01/09 23:16:05]

Done.

+}
+
+static void sendAck(const std::string& mailbox_name,

[Fady Samuel, 2013/01/09 21:23:38]

SendACK

+                    int host_route_id,
+                    int gpu_route_id,
+                    int gpu_host_id,
+                    unsigned syncPoint) {

[Fady Samuel, 2013/01/09 21:23:38]

sync_point

+  RenderThread::Get()->Send(
+      new BrowserPluginHostMsg_BuffersSwappedACK(
+          host_route_id,
+          gpu_route_id,
+          gpu_host_id,
+          mailbox_name,
+          syncPoint));

[Fady Samuel, 2013/01/09 21:23:38]

sync_point

+}
+
+void BrowserPluginCompositingHelper::OnBuffersSwapped(const gfx::Size& size,
+                                               const std::string& mailbox_name,
+                                               int gpu_route_id,
+                                               int gpu_host_id) {
+  if (!last_mailbox_valid_)
+    sendAck(std::string(), host_routing_id_, gpu_route_id, gpu_host_id, 0);
+
+  last_mailbox_valid_ = !mailbox_name.empty();
+  texture_layer_->setTextureMailbox(mailbox_name,
+                                    base::Bind(&sendAck,
+                                               mailbox_name,
+                                               host_routing_id_,
+                                               gpu_route_id,
+                                               gpu_host_id));
+}
+
+}  // namespace content