From 6d3a46e4e0238baf7373e46ce744811b434d476e Mon Sep 17 00:00:00 2001
From: "alexst@chromium.org"
 <alexst@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98>
Date: Mon, 25 Nov 2013 23:08:53 +0000
Subject: [PATCH] Allow browser plugin compositing helper to enable
 transparency in webview.

BUG=157628

Review URL: https://codereview.chromium.org/40563003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237171 0039d316-1c4b-4281-b951-d872f2087c98
---
 .../browser_plugin_compositing_helper.cc           | 28 ++++++++++++++++------
 .../browser_plugin_compositing_helper.h            |  8 ++++---
 2 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/content/renderer/browser_plugin/browser_plugin_compositing_helper.cc b/content/renderer/browser_plugin/browser_plugin_compositing_helper.cc
index 54704bce33bd..1678423f2af3 100644
--- a/content/renderer/browser_plugin/browser_plugin_compositing_helper.cc
+++ b/content/renderer/browser_plugin/browser_plugin_compositing_helper.cc
@@ -44,6 +44,7 @@ BrowserPluginCompositingHelper::BrowserPluginCompositingHelper(
       last_mailbox_valid_(false),
       ack_pending_(true),
       software_ack_pending_(false),
+      opaque_(true),
       container_(container),
       browser_plugin_manager_(manager) {
 }
@@ -100,7 +101,7 @@ void BrowserPluginCompositingHelper::EnableCompositing(bool enable) {
   container_->setWebLayer(enable ? web_layer_.get() : NULL);
 }
 
-void BrowserPluginCompositingHelper::CheckSizeAndAdjustLayerBounds(
+void BrowserPluginCompositingHelper::CheckSizeAndAdjustLayerProperties(
     const gfx::Size& new_size,
     float device_scale_factor,
     cc::Layer* layer) {
@@ -113,6 +114,10 @@ void BrowserPluginCompositingHelper::CheckSizeAndAdjustLayerBounds(
         gfx::ScaleSize(buffer_size_, 1.0f / device_scale_factor));
     layer->SetBounds(device_scale_adjusted_size);
   }
+
+  // Manually manage background layer for transparent webview.
+  if (!opaque_)
+    background_layer_->SetIsDrawable(false);
 }
 
 void BrowserPluginCompositingHelper::MailboxReleased(
@@ -227,7 +232,7 @@ void BrowserPluginCompositingHelper::OnBuffersSwappedPrivate(
   if (!texture_layer_.get()) {
     texture_layer_ = cc::TextureLayer::CreateForMailbox(NULL);
     texture_layer_->SetIsDrawable(true);
-    texture_layer_->SetContentsOpaque(true);
+    SetContentsOpaque(opaque_);
 
     background_layer_->AddChild(texture_layer_);
   }
@@ -242,9 +247,9 @@ void BrowserPluginCompositingHelper::OnBuffersSwappedPrivate(
   // when a new buffer arrives.
   // Visually, this will either display a smaller part of the buffer
   // or introduce a gutter around it.
-  CheckSizeAndAdjustLayerBounds(mailbox.size,
-                                device_scale_factor,
-                                texture_layer_.get());
+  CheckSizeAndAdjustLayerProperties(mailbox.size,
+                                    device_scale_factor,
+                                    texture_layer_.get());
 
   bool is_software_frame = mailbox.type == SOFTWARE_COMPOSITOR_FRAME;
   bool current_mailbox_valid = is_software_frame ?
@@ -392,13 +397,13 @@ void BrowserPluginCompositingHelper::OnCompositorFrameSwapped(
     delegated_layer_ =
         cc::DelegatedRendererLayer::Create(NULL, frame_provider_.get());
     delegated_layer_->SetIsDrawable(true);
-    delegated_layer_->SetContentsOpaque(true);
+    SetContentsOpaque(opaque_);
     background_layer_->AddChild(delegated_layer_);
   } else {
     frame_provider_->SetFrameData(frame->delegated_frame_data.Pass());
   }
 
-  CheckSizeAndAdjustLayerBounds(
+  CheckSizeAndAdjustLayerProperties(
       frame_data->render_pass_list.back()->output_rect.size(),
       frame->metadata.device_scale_factor,
       delegated_layer_.get());
@@ -436,4 +441,13 @@ void BrowserPluginCompositingHelper::SendReturnedDelegatedResources() {
           ack));
 }
 
+void BrowserPluginCompositingHelper::SetContentsOpaque(bool opaque) {
+  opaque_ = opaque;
+
+  if (texture_layer_.get())
+    texture_layer_->SetContentsOpaque(opaque_);
+  if (delegated_layer_.get())
+    delegated_layer_->SetContentsOpaque(opaque_);
+}
+
 }  // namespace content
diff --git a/content/renderer/browser_plugin/browser_plugin_compositing_helper.h b/content/renderer/browser_plugin/browser_plugin_compositing_helper.h
index 4e836c6f180d..dcbd6a2ad686 100644
--- a/content/renderer/browser_plugin/browser_plugin_compositing_helper.h
+++ b/content/renderer/browser_plugin/browser_plugin_compositing_helper.h
@@ -62,6 +62,7 @@ class CONTENT_EXPORT BrowserPluginCompositingHelper :
 
   // cc::DelegatedFrameProviderClient implementation.
   virtual void UnusedResourcesAreAvailable() OVERRIDE;
+  void SetContentsOpaque(bool);
 
  protected:
   // Friend RefCounted so that the dtor can be non-public.
@@ -85,9 +86,9 @@ class CONTENT_EXPORT BrowserPluginCompositingHelper :
     base::SharedMemory* shared_memory;
   };
   virtual ~BrowserPluginCompositingHelper();
-  void CheckSizeAndAdjustLayerBounds(const gfx::Size& new_size,
-                                     float device_scale_factor,
-                                     cc::Layer* layer);
+  void CheckSizeAndAdjustLayerProperties(const gfx::Size& new_size,
+                                         float device_scale_factor,
+                                         cc::Layer* layer);
   void OnBuffersSwappedPrivate(const SwapBuffersInfo& mailbox,
                                unsigned sync_point,
                                float device_scale_factor);
@@ -104,6 +105,7 @@ class CONTENT_EXPORT BrowserPluginCompositingHelper :
   bool last_mailbox_valid_;
   bool ack_pending_;
   bool software_ack_pending_;
+  bool opaque_;
   std::vector<unsigned> unacked_software_frames_;
 
   gfx::Size buffer_size_;
-- 
2.11.4.GIT