Inform webkit when PPAPI plugin contents are opaque.

content/renderer/pepper/pepper_platform_context_3d_impl.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 "content/renderer/pepper/pepper_platform_context_3d_impl.h"
 
 #include "base/bind.h"
 #include "content/common/gpu/client/content_gl_context.h"
 #include "content/common/gpu/client/gpu_channel_host.h"
 #include "content/common/gpu/client/command_buffer_proxy.h"
 #include "content/renderer/pepper/pepper_parent_context_provider.h"
 #include "content/renderer/render_thread_impl.h"
 #include "googleurl/src/gurl.h"
 #include "gpu/command_buffer/client/gles2_cmd_helper.h"
 #include "gpu/command_buffer/client/gles2_implementation.h"
 #include "ui/gfx/gl/gpu_preference.h"
 
 #ifdef ENABLE_GPU
 
 PlatformContext3DImpl::PlatformContext3DImpl(
     PepperParentContextProvider* parent_context_provider)
       : parent_context_provider_(parent_context_provider),
         parent_texture_id_(0),
+        has_alpha_(false),
         command_buffer_(NULL),
         weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
 }
 
 PlatformContext3DImpl::~PlatformContext3DImpl() {
   if (parent_context_.get() && parent_texture_id_ != 0) {
     // Flush any remaining commands in the parent context to make sure the
     // texture id accounting stays consistent.
     gpu::gles2::GLES2Implementation* parent_gles2 =
         parent_context_->GetImplementation();
@@ skipping 57 matching lines @@
     for (const int32_t* attr = attrib_list;
          attr[0] != ContentGLContext::NONE;
          attr += 2) {
       switch (attr[0]) {
         case ContentGLContext::WIDTH:
           surface_size.set_width(attr[1]);
           break;
         case ContentGLContext::HEIGHT:
           surface_size.set_height(attr[1]);
           break;
+        case ContentGLContext::ALPHA_SIZE:
+          has_alpha_ = attr[1] > 0;
+        // fall-through
         default:
           attribs.push_back(attr[0]);
           attribs.push_back(attr[1]);
           break;
       }
     }
     attribs.push_back(ContentGLContext::NONE);
   }
 
   command_buffer_ = channel_->CreateOffscreenCommandBuffer(
@@ skipping 34 matching lines @@
     return false;
 
   return true;
 }
 
 unsigned PlatformContext3DImpl::GetBackingTextureId() {
   DCHECK(command_buffer_);
   return parent_texture_id_;
 }
 
+bool PlatformContext3DImpl::IsOpaque() {
+  DCHECK(command_buffer_);
+  return !has_alpha_;
+}
+
 gpu::CommandBuffer* PlatformContext3DImpl::GetCommandBuffer() {
   return command_buffer_;
 }
 
 int PlatformContext3DImpl::GetCommandBufferRouteId() {
   DCHECK(command_buffer_);
   return command_buffer_->route_id();
 }
 
 void PlatformContext3DImpl::SetContextLostCallback(const base::Closure& task) {
   context_lost_callback_ = task;
 }
 
 bool PlatformContext3DImpl::Echo(const base::Closure& task) {
   return command_buffer_->Echo(task);
 }
 
 void PlatformContext3DImpl::OnContextLost() {
   DCHECK(command_buffer_);
 
   if (!context_lost_callback_.is_null())
     context_lost_callback_.Run();
 }
 
 #endif  // ENABLE_GPU