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

ui/compositor/compositor.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 "ui/compositor/compositor.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/threading/thread_restrictions.h"
@@ skipping 144 matching lines @@
   settings.perTilePainting =
       command_line->HasSwitch(switches::kUIEnablePerTilePainting);
 #endif
 
   host_.initialize(this, root_web_layer_, settings);
   host_.setSurfaceReady();
   root_web_layer_.setAnchorPoint(WebKit::WebFloatPoint(0.f, 0.f));
 }
 
 Compositor::~Compositor() {
+  // Clear out any pending callbacks.
+  didCommit();

[piman, 2012/07/12 17:42:27]

Is this still needed? I figure by the time we get here, the RWHVA will have been
removed from the tree and so they will do whatever is necessary to execute their
callbacks before then.
I guess my main question is what makes didCommit special as opposed to all the
other ones in CompositorObserver.

[jonathan.backer, 2012/07/13 13:26:24]

You're right. There's nothing special. We'll leave it up to the
CompositorObserver. I checked with breakpoints and we're covered.

Done.

+
   // Don't call |CompositorDelegate::ScheduleDraw| from this point.
   delegate_ = NULL;
   // There's a cycle between |root_web_layer_| and |host_|, which results in
   // leaking and/or crashing. Explicitly set the root layer to NULL so the cycle
   // is broken.
   host_.setRootLayer(NULL);
   if (root_layer_)
     root_layer_->SetCompositor(NULL);
+
+  // Stop all outstanding draws before telling the ContextFactory to tear
+  // down any contexts that the |host_| may rely upon.
+  host_.reset();
+
   if (!test_compositor_enabled)
     ContextFactory::GetInstance()->RemoveCompositor(this);
 }
 
 void Compositor::Initialize(bool use_thread) {
 #if defined(WEBCOMPOSITOR_OWNS_SETTINGS)
   CommandLine* command_line = CommandLine::ForCurrentProcess();
   // These settings must be applied before we initialize the compositor.
   WebKit::WebCompositor::setPartialSwapEnabled(
       command_line->HasSwitch(switches::kUIEnablePartialSwap));
@@ skipping 102 matching lines @@
 }
 
 void Compositor::RemoveObserver(CompositorObserver* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
 bool Compositor::HasObserver(CompositorObserver* observer) {
   return observer_list_.HasObserver(observer);
 }
 
+bool Compositor::IsThreaded() const {
+  return g_compositor_thread != NULL;
+}
+
 void Compositor::OnSwapBuffersPosted() {
   swap_posted_ = true;
 }
 
 void Compositor::OnSwapBuffersComplete() {
   DCHECK(swap_posted_);
   swap_posted_ = false;
   NotifyEnd();
 }
 
@@ skipping 30 matching lines @@
     test_context->Initialize();
     return test_context;
   } else {
     return ContextFactory::GetInstance()->CreateContext(this);
   }
 }
 
 void Compositor::didRebindGraphicsContext(bool success) {
 }
 
+// Called once per draw in single-threaded compositor mode and potentially
+// many times between draws in the multi-threaded compositor mode.
+void Compositor::didCommit() {
+  FOR_EACH_OBSERVER(CompositorObserver,
+                    observer_list_,
+                    OnCompositingDidCommit(this));
+}
+
 void Compositor::didCommitAndDrawFrame() {
   // TODO(backer): Plumb through an earlier impl side will start.
   if (g_compositor_thread)
     FOR_EACH_OBSERVER(CompositorObserver,
                       observer_list_,
                       OnCompositingWillStart(this));
 
   FOR_EACH_OBSERVER(CompositorObserver,
                     observer_list_,
                     OnCompositingStarted(this));
@@ skipping 53 matching lines @@
 
 COMPOSITOR_EXPORT void DisableTestCompositor() {
   test_compositor_enabled = false;
 }
 
 COMPOSITOR_EXPORT bool IsTestCompositorEnabled() {
   return test_compositor_enabled;
 }
 
 }  // namespace ui