Bug 1128454 - When plugin bridging mysteriously fails, log the ipc channel state along with the nsresult error code. r=billm

dom/plugins/ipc/PluginModuleParent.cpp

@@ -135,7 +135,7 @@ mozilla::plugins::SetupBridge(uint32_t aPluginId,
         // We are going to abort due to the failure, lets note the cause
         // in the report for diagnosing.
         nsAutoCString error;
-        error.AppendPrintf("%X", *rv);
+        error.AppendPrintf("%X %d", *rv, chromeParent->GetIPCChannel()->GetChannelState__TotallyRacy());
         CrashReporter::AnnotateCrashReport(NS_LITERAL_CSTRING("BridgePluginError"), error);
 #endif
       return false;

ipc/glue/MessageChannel.h

@@ -129,6 +129,11 @@ class MessageChannel : HasResultCodes
 
     bool CanSend() const;
 
+    // Currently only for debugging purposes, doesn't aquire mMonitor.
+    ChannelState GetChannelState__TotallyRacy() const {
+        return mChannelState;
+    }
+
     void SetReplyTimeoutMs(int32_t aTimeoutMs);
 
     bool IsOnCxxStack() const {