<webview>: Expose transparency API

content/renderer/browser_plugin/browser_plugin.cc

Index: content/renderer/browser_plugin/browser_plugin.cc
diff --git a/content/renderer/browser_plugin/browser_plugin.cc b/content/renderer/browser_plugin/browser_plugin.cc
index 192f64c76d261a81d50df4d6b3e540989c1ca68e..178f96d70aef03dedef3df2c3b25caf5bc839201 100644
--- a/content/renderer/browser_plugin/browser_plugin.cc
+++ b/content/renderer/browser_plugin/browser_plugin.cc
@@ -86,7 +86,6 @@ BrowserPlugin::BrowserPlugin(
       content_window_routing_id_(MSG_ROUTING_NONE),
       plugin_focused_(false),
       visible_(true),
-      opaque_(true),
       before_first_navigation_(true),
       mouse_locked_(false),
       browser_plugin_manager_(render_view->GetBrowserPluginManager()),
@@ -182,6 +181,10 @@ std::string BrowserPlugin::GetNameAttribute() const {
   return GetDOMAttributeValue(browser_plugin::kAttributeName);
 }
 
+bool BrowserPlugin::GetAllowTransparencyAttribute() const {
+  return HasDOMAttribute(browser_plugin::kAttributeAllowTransparency);
+}
+
 std::string BrowserPlugin::GetSrcAttribute() const {
   return GetDOMAttributeValue(browser_plugin::kAttributeSrc);
 }
@@ -259,6 +262,21 @@ void BrowserPlugin::ParseNameAttribute() {
                                        GetNameAttribute()));
 }
 
+void BrowserPlugin::ParseAllowTransparencyAttribute() {
+  if (!HasGuestInstanceID())
+    return;
+
+  bool opaque = !GetAllowTransparencyAttribute();
+
+  if (compositing_helper_)
+    compositing_helper_->SetContentsOpaque(opaque);
+
+  browser_plugin_manager()->Send(new BrowserPluginHostMsg_SetContentsOpaque(
+        render_view_routing_id_,
+        guest_instance_id_,
+        opaque));
+}
+
 bool BrowserPlugin::ParseSrcAttribute(std::string* error_message) {
   if (!valid_partition_id_) {
     *error_message = browser_plugin::kErrorInvalidPartition;
@@ -372,7 +390,7 @@ void BrowserPlugin::Attach(scoped_ptr<base::DictionaryValue> extra_params) {
   BrowserPluginHostMsg_Attach_Params attach_params;
   attach_params.focused = ShouldGuestBeFocused();
   attach_params.visible = visible_;
-  attach_params.opaque = opaque_;
+  attach_params.opaque = !GetAllowTransparencyAttribute();
   attach_params.name = GetNameAttribute();
   attach_params.storage_partition_id = storage_partition_id_;
   attach_params.persist_storage = persist_storage_;
@@ -393,23 +411,6 @@ void BrowserPlugin::DidCommitCompositorFrame() {
     compositing_helper_->DidCommitCompositorFrame();
 }
 
-void BrowserPlugin::SetContentsOpaque(bool opaque) {
-  if (opaque_ == opaque)
-    return;
-
-  opaque_ = opaque;
-  if (!HasGuestInstanceID())
-    return;
-
-  if (compositing_helper_)
-    compositing_helper_->SetContentsOpaque(opaque_);
-
-  browser_plugin_manager()->Send(new BrowserPluginHostMsg_SetContentsOpaque(
-        render_view_routing_id_,
-        guest_instance_id_,
-        opaque_));
-}
-
 void BrowserPlugin::OnAdvanceFocus(int guest_instance_id, bool reverse) {
   DCHECK(render_view_.get());
   render_view_->GetWebView()->advanceFocus(reverse);
@@ -922,7 +923,7 @@ void BrowserPlugin::EnableCompositing(bool enable) {
     }
   }
   compositing_helper_->EnableCompositing(enable);
-  compositing_helper_->SetContentsOpaque(opaque_);
+  compositing_helper_->SetContentsOpaque(!GetAllowTransparencyAttribute());
 }
 
 void BrowserPlugin::destroy() {