Use a placeholder instead of the default plugin for missing plug-ins on Mac and Linux.

content/common/view_messages.h

Index: content/common/view_messages.h
diff --git a/content/common/view_messages.h b/content/common/view_messages.h
index ea9b902e8bf5917d2178659b877425cb96d73288..cdb955262e2b3f0cfb6f3d4b5d465cb8adbd5894 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -1474,14 +1474,14 @@ IPC_SYNC_MESSAGE_CONTROL1_1(ViewHostMsg_GetPlugins,
 // |actual_mime_type| is the actual mime type supported by the
 // plugin found that match the URL given (one for each item in
 // |info|).
-IPC_SYNC_MESSAGE_CONTROL4_3(ViewHostMsg_GetPluginInfo,
+IPC_SYNC_MESSAGE_CONTROL4_3(ViewHostMsg_GetMatchingPlugins,
                             int /* routing_id */,
                             GURL /* url */,
                             GURL /* page_url */,
                             std::string /* mime_type */,
-                            bool /* found */,
-                            webkit::WebPluginInfo /* plugin info */,
-                            std::string /* actual_mime_type */)
+                            std::vector<webkit::WebPluginInfo> /* plugins */,
+                            std::vector<std::string> /* mime_types */,
+                            std::vector<bool> /* allowed */)
 
 // A renderer sends this to the browser process when it wants to
 // create a plugin.  The browser will create the plugin process if