Add PpapiDecryptor which wraps a CDM plugin.

webkit/media/webmediaplayer_impl.h

Index: webkit/media/webmediaplayer_impl.h
diff --git a/webkit/media/webmediaplayer_impl.h b/webkit/media/webmediaplayer_impl.h
index 376c10f152816326b9e42245d03d1f6160a2be4c..e1cad0b15e6d932fd929387d157018243599c8b4 100644
--- a/webkit/media/webmediaplayer_impl.h
+++ b/webkit/media/webmediaplayer_impl.h
@@ -267,6 +267,12 @@ class WebMediaPlayerImpl
   // Getter method to |client_|.
   WebKit::WebMediaPlayerClient* GetClient();
 
+  // Create a plugin instance based on the |plugin_type|.
+  // TODO(xhwang): Change WebMediaPlayerClient::createHelperPlugin()'s
+  // parameter order so this can be replaced by a base::Bind().
+  scoped_refptr<webkit::ppapi::PluginInstance> CreatePluginInstance(
+      const std::string& plugin_type);
+
   // Lets V8 know that player uses extra resources not managed by V8.
   void IncrementExternallyAllocatedMemory();