Fix painting glitch with text and NPAPI plugins. This was a regression from r167042. The problem wa…

webkit/plugins/npapi/plugin_instance.h

 // 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.
 
 // TODO: Need to deal with NPAPI's NPSavedData.
 //       I haven't seen plugins use it yet.
 
 #ifndef WEBKIT_PLUGINS_NPAPI_PLUGIN_INSTANCE_H_
 #define WEBKIT_PLUGINS_NPAPI_PLUGIN_INSTANCE_H_
 
@@ skipping 67 matching lines @@
   gfx::PluginWindowHandle window_handle() const { return window_handle_; }
   void set_window_handle(gfx::PluginWindowHandle value) {
     window_handle_ = value;
   }
 
   // Get/Set whether this instance is in Windowless mode.
   // Default is false.
   bool windowless() { return windowless_; }
   void set_windowless(bool value) { windowless_ = value; }
 
-  // Get/Set whether this instance is transparent.
-  // This only applies to windowless plugins.  Transparent
-  // plugins require that webkit paint the background.
-  // Default is true.
+  // Get/Set whether this instance is transparent. This only applies to
+  // windowless plugins.  Transparent plugins require that webkit paint the
+  // background.
+  // Default is true for all plugins other than Flash. For Flash, we default to
+  // opaque since it always tells us if it's transparent during NPP_New.
   bool transparent() { return transparent_; }
   void set_transparent(bool value) { transparent_ = value; }
 
   // Get/Set the WebPlugin associated with this instance
   WebPlugin* webplugin() { return webplugin_; }
   void set_web_plugin(WebPlugin* webplugin) {
     webplugin_ = webplugin;
   }
 
   // Get the mimeType for this plugin stream
@@ skipping 260 matching lines @@
  private:
   scoped_refptr<PluginInstance> instance_;
   DISALLOW_COPY_AND_ASSIGN(ScopedCurrentPluginEvent);
 };
 #endif
 
 }  // namespace npapi
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_NPAPI_PLUGIN_INSTANCE_H_