Ignore certain messages in plugin broker process if they are not sent by the

content/ppapi_plugin/broker_process_dispatcher.cc

Index: content/ppapi_plugin/broker_process_dispatcher.cc
diff --git a/content/ppapi_plugin/broker_process_dispatcher.cc b/content/ppapi_plugin/broker_process_dispatcher.cc
index 01325531cd35cee481b92a516d4f8831204b2031..b971f7ad015f42864a8d9bad8ce690125027d480 100644
--- a/content/ppapi_plugin/broker_process_dispatcher.cc
+++ b/content/ppapi_plugin/broker_process_dispatcher.cc
@@ -77,12 +77,14 @@ void GetPermissionSettingsCallback(
 
 BrokerProcessDispatcher::BrokerProcessDispatcher(
     PP_GetInterface_Func get_plugin_interface,
-    PP_ConnectInstance_Func connect_instance)
+    PP_ConnectInstance_Func connect_instance,
+    bool peer_is_browser)
     : ppapi::proxy::BrokerSideDispatcher(connect_instance),
       get_plugin_interface_(get_plugin_interface),
       flash_browser_operations_1_3_(NULL),
       flash_browser_operations_1_2_(NULL),
-      flash_browser_operations_1_0_(NULL) {
+      flash_browser_operations_1_0_(NULL),
+      peer_is_browser_(peer_is_browser) {
   if (get_plugin_interface) {
     flash_browser_operations_1_0_ =
         static_cast<const PPP_Flash_BrowserOperations_1_0*>(
@@ -110,17 +112,25 @@ BrokerProcessDispatcher::~BrokerProcessDispatcher() {
 }
 
 bool BrokerProcessDispatcher::OnMessageReceived(const IPC::Message& msg) {
+  if (BrokerSideDispatcher::OnMessageReceived(msg))
+    return true;
+
+  if (!peer_is_browser_)

[jschuh, 2016/06/16 21:08:36]

This seems like a case where we want to terminate the peer.

[yzshen1, 2016/06/16 22:23:15]

I agree that it would be nice if we can kill the peer.

The problem is that this process (the plugin) doesn't have the capability to do
that. Even if we add support for this plugin process to send a request to the
browser process to do that, the browser probably shouldn't trust the words of a
plugin process to terminate a renderer process.

Do you think I could land this CL without that? Thanks!

+    return false;
+
+  bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(BrokerProcessDispatcher, msg)
     IPC_MESSAGE_HANDLER(PpapiMsg_GetSitesWithData, OnGetSitesWithData)
     IPC_MESSAGE_HANDLER(PpapiMsg_ClearSiteData, OnClearSiteData)
     IPC_MESSAGE_HANDLER(PpapiMsg_DeauthorizeContentLicenses,
                         OnDeauthorizeContentLicenses)
-    IPC_MESSAGE_HANDLER(PpapiMsg_GetPermissionSettings, OnGetPermissionSettings)
+    IPC_MESSAGE_HANDLER(PpapiMsg_GetPermissionSettings,
+                        OnGetPermissionSettings)
     IPC_MESSAGE_HANDLER(PpapiMsg_SetDefaultPermission, OnSetDefaultPermission)
     IPC_MESSAGE_HANDLER(PpapiMsg_SetSitePermission, OnSetSitePermission)
-    IPC_MESSAGE_UNHANDLED(return BrokerSideDispatcher::OnMessageReceived(msg))
+    IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
-  return true;
+  return handled;
 }
 
 void BrokerProcessDispatcher::OnGetPermissionSettingsCompleted(