Aura: Have ui::Layer implement WebKit::WebExternalTextureLayerClient

With --ui-enable-threaded-compositing, every Layer::SetExternalTexture() was causing a heavy CCThreadProxy::acquireLayerTextures(). This synchronization is unnecessary on the common case of buffer flips, because RWHVA handles the necessary synchronization via OnCompositingWillStart callbacks.

To reduce the synchronization burden, we handle
- wait for a commit on resize fast ACKS
- handle the common case of buffer flips via WebExternalTextureLayerClient::prepareTexture()
- and explicitly call WebExternalTextureLayer::willModifyTexture() when we need the extra synchronization on tear down.

BUG=136012
TEST=none

Review URL: https://chromiumcodereview.appspot.com/10689108

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@146621 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 7 insertions, 0 deletions

diff --git a/ui/aura/bench/bench_main.cc b/ui/aura/bench/bench_main.cc
index 7d416757..0430901 100644
--- a/ui/aura/bench/bench_main.cc
+++ b/ui/aura/bench/bench_main.cc
@@ -91,6 +91,9 @@ class BenchCompositorObserver : public ui::CompositorObserver {
         frames_(0),
         max_frames_(max_frames) {
   }
+
+  virtual void OnCompositingDidCommit(ui::Compositor* compositor) OVERRIDE {}
+
   virtual void OnCompositingWillStart(Compositor* compositor) OVERRIDE {}
 
   virtual void OnCompositingStarted(Compositor* compositor) OVERRIDE {}
@@ -144,6 +147,10 @@ class WebGLTexture : public ui::Texture {
                          GL_RGBA, GL_UNSIGNED_BYTE, NULL);
   }
 
+  virtual WebGraphicsContext3D* HostContext3D() OVERRIDE {
+    return context_;
+  }
+
  private:
   virtual ~WebGLTexture() {
     context_->deleteTexture(texture_id());