aura: Allow delegated frames to be used by more than one impl layer.

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/layers/delegated_frame_provider.h"
+#include "cc/layers/delegated_frame_resource_collection.h"
 #include "cc/layers/delegated_renderer_layer.h"
 #include "cc/layers/solid_color_layer.h"
 #include "cc/layers/texture_layer.h"
 #include "cc/output/context_provider.h"
 #include "cc/resources/single_release_callback.h"
 #include "content/common/browser_plugin/browser_plugin_messages.h"
 #include "content/common/gpu/client/context_provider_command_buffer.h"
 #include "content/renderer/browser_plugin/browser_plugin_manager.h"
 #include "content/renderer/render_thread_impl.h"
 #include "third_party/WebKit/public/platform/WebGraphicsContext3D.h"
@@ skipping 44 matching lines @@
         new BrowserPluginHostMsg_CompositorFrameACK(
             host_routing_id_,
             instance_id_,
             last_route_id_,
             last_output_surface_id_,
             last_host_id_,
             ack));
 
     software_ack_pending_ = false;
   }
-  if (!delegated_layer_.get() || !ack_pending_)
+  if (!resource_collection_.get() || !ack_pending_)
     return;
 
   cc::CompositorFrameAck ack;
-  delegated_layer_->TakeUnusedResourcesForChildCompositor(&ack.resources);
+  resource_collection_->TakeUnusedResourcesForChildCompositor(&ack.resources);
 
   browser_plugin_manager_->Send(
       new BrowserPluginHostMsg_CompositorFrameACK(
           host_routing_id_,
           instance_id_,
           last_route_id_,
           last_output_surface_id_,
           last_host_id_,
           ack));
 
@@ skipping 244 matching lines @@
     OnBuffersSwappedPrivate(swap_info, 0,
                             frame->metadata.device_scale_factor);
     software_ack_pending_ = true;
     last_route_id_ = route_id;
     last_output_surface_id_ = output_surface_id;
     last_host_id_ = host_id;
     return;
   }
 
   DCHECK(!texture_layer_.get());
-  if (!delegated_layer_.get()) {
-    delegated_layer_ = cc::DelegatedRendererLayer::Create(NULL);
-    delegated_layer_->SetIsDrawable(true);
-    delegated_layer_->SetContentsOpaque(true);
 
-    background_layer_->AddChild(delegated_layer_);
-  }
-
-  cc::DelegatedFrameData *frame_data = frame->delegated_frame_data.get();
+  cc::DelegatedFrameData* frame_data = frame->delegated_frame_data.get();
   if (!frame_data)
     return;
 
   CheckSizeAndAdjustLayerBounds(
       frame_data->render_pass_list.back()->output_rect.size(),
       frame->metadata.device_scale_factor,
       delegated_layer_.get());
 
-  delegated_layer_->SetFrameData(frame->delegated_frame_data.Pass());
+  DCHECK_NE(0u, frame_data->render_pass_list.size());

[piman, 2013/10/04 23:42:25]

nit: DCHECK(!frame_data->render_pass_list.empty());

[danakj, 2013/10/07 21:57:39]

Done.

+  cc::RenderPass* root_pass = frame_data->render_pass_list.back();
+  gfx::Size frame_size = root_pass->output_rect.size();
+
+  if (!resource_collection_) {
+    // TODO(danakj): Could return resources sooner if we gave a client here and
+    // listened for UnusedResourcesAreAvailable().
+    resource_collection_.reset(new cc::DelegatedFrameResourceCollection(NULL));
+  }
+  if (!frame_provider_ || frame_provider_->frame_size() != frame_size) {
+    frame_provider_.reset(new cc::DelegatedFrameProvider(
+        resource_collection_.get(), frame->delegated_frame_data.Pass()));
+    delegated_layer_ =
+        cc::DelegatedRendererLayer::Create(NULL, frame_provider_.get());
+    delegated_layer_->SetIsDrawable(true);
+    delegated_layer_->SetContentsOpaque(true);
+    background_layer_->AddChild(delegated_layer_);
+  } else {
+    frame_provider_->SetFrameData(frame->delegated_frame_data.Pass());
+  }
+
   last_route_id_ = route_id;
   last_output_surface_id_ = output_surface_id;
   last_host_id_ = host_id;
   ack_pending_ = true;
 }
 
 void BrowserPluginCompositingHelper::UpdateVisibility(bool visible) {
   if (texture_layer_.get())
     texture_layer_->SetIsDrawable(visible);
   if (delegated_layer_.get())
     delegated_layer_->SetIsDrawable(visible);
 }
 
 }  // namespace content