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();
+
   // 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 152 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 (std::vector< base::Callback<void(Compositor*)> >::const_iterator
+      it = did_commit_callbacks_.begin();
+      it != did_commit_callbacks_.end(); ++it) {
+    it->Run(this);

[piman, 2012/07/12 00:18:09]

btw, you run the risk of the closure modifying did_commit_callbacks_.
FWIW FOR_EACH_OBSERVER deals with this correctly.

+  }
+  did_commit_callbacks_.clear();
+}
+
 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));
 }
 
 void Compositor::didCompleteSwapBuffers() {
   NotifyEnd();
 }
 
 void Compositor::scheduleComposite() {
   if (!disable_schedule_composite_)
     ScheduleDraw();
 }
 
+void Compositor::AddDidCommitCallback(
+    const base::Callback<void(ui::Compositor*)>& callback) {
+  did_commit_callbacks_.push_back(callback);
+}
+
 void Compositor::SwizzleRGBAToBGRAAndFlip(unsigned char* pixels,
                                           const gfx::Size& image_size) {
   // Swizzle from RGBA to BGRA
   size_t bitmap_size = 4 * image_size.width() * image_size.height();
   for (size_t i = 0; i < bitmap_size; i += 4)
     std::swap(pixels[i], pixels[i + 2]);
 
   // Vertical flip to transform from GL co-ords
   size_t row_size = 4 * image_size.width();
   scoped_array<unsigned char> tmp_row(new unsigned char[row_size]);
@@ skipping 32 matching lines @@
 
 COMPOSITOR_EXPORT void DisableTestCompositor() {
   test_compositor_enabled = false;
 }
 
 COMPOSITOR_EXPORT bool IsTestCompositorEnabled() {
   return test_compositor_enabled;
 }
 
 }  // namespace ui