Make AutomationProvider fail fast on messages it doesn't understand.

This prevents an awful debugging experience where things just silently hang.

TEST=none
BUG=none

Review URL: http://codereview.chromium.org/3224001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@57907 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 17 insertions, 0 deletions

diff --git a/chrome/browser/automation/automation_provider.cc b/chrome/browser/automation/automation_provider.cc
index 418738a..87578db 100644
--- a/chrome/browser/automation/automation_provider.cc
+++ b/chrome/browser/automation/automation_provider.cc
@@ -361,9 +361,24 @@ void AutomationProvider::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER_DELAY_REPLY(AutomationMsg_LoginWithUserAndPass,
                                     LoginWithUserAndPass)
 #endif  // defined(OS_CHROMEOS)
+
+    IPC_MESSAGE_UNHANDLED(OnUnhandledMessage());
   IPC_END_MESSAGE_MAP()
 }
 
+void AutomationProvider::OnUnhandledMessage() {
+  // We should not hang here. Print a message to indicate what's going on,
+  // and disconnect the channel to notify the caller about the error
+  // in a way it can't ignore, and make any further attempts to send
+  // messages fail fast.
+  LOG(ERROR) << "AutomationProvider received a message it can't handle. "
+             << "Please make sure that you use switches::kTestingChannelID "
+             << "for test code (TestingAutomationProvider), and "
+             << "switches::kAutomationClientChannelID for everything else "
+             << "(like ChromeFrame). Closing the automation channel.";
+  channel_->Close();
+}
+
 void AutomationProvider::ShutdownSessionService(int handle, bool* result) {
   if (browser_tracker_->ContainsHandle(handle)) {
     Browser* browser = browser_tracker_->GetResource(handle);
diff --git a/chrome/browser/automation/automation_provider.h b/chrome/browser/automation/automation_provider.h
index 34967f3..ff859591 100644
--- a/chrome/browser/automation/automation_provider.h
+++ b/chrome/browser/automation/automation_provider.h
@@ -191,6 +191,8 @@ class AutomationProvider : public base::RefCounted<AutomationProvider>,
   CancelableRequestConsumer consumer_;
 
  private:
+  void OnUnhandledMessage();
+
   // IPC Message callbacks.
   void ShutdownSessionService(int handle, bool* result);
   void WindowSimulateDrag(int handle,