Add a check to the registry before the intent infobar is shown.

chrome/browser/intents/register_intent_handler_infobar_delegate.h

Index: chrome/browser/intents/register_intent_handler_infobar_delegate.h
diff --git a/chrome/browser/intents/register_intent_handler_infobar_delegate.h b/chrome/browser/intents/register_intent_handler_infobar_delegate.h
index 83ae2fa75956d7e52a58bbd96740db7b0a8a7c24..8142ada78843895ad3f86c35bc242135aa2170e8 100644
--- a/chrome/browser/intents/register_intent_handler_infobar_delegate.h
+++ b/chrome/browser/intents/register_intent_handler_infobar_delegate.h
@@ -11,6 +11,7 @@
 #include "chrome/browser/tab_contents/confirm_infobar_delegate.h"
 #include "webkit/glue/web_intent_service_data.h"
 
+class InfoBarTabHelper;
 class TabContents;
 class WebIntentsRegistry;
 
@@ -30,6 +31,17 @@ class RegisterIntentHandlerInfoBarDelegate : public ConfirmInfoBarDelegate {
   virtual string16 GetLinkText() const OVERRIDE;
   virtual bool LinkClicked(WindowOpenDisposition disposition) OVERRIDE;
 
+  // This helper method checks the registry to see if the indicated service has
+  // already been registered. If all registration details are the same, it does

[James Hawkins, 2011/10/29 21:41:32]

This second sentence should probably be reworded to reflect what the method does
instead of what it does not do.  The whole thing could be simplified to:

"Shows the intent registration InfoBar iff |service| has not already been
registered."

[Greg Billock, 2011/10/31 17:07:09]

I like that.

+  // not show the infobar.
+  // |infobar_helper| is the infobar controller for the tab in which the infobar
+  // may be shown. Must not be null.
+  // |registry| is the data source for web intents. Must not be null.
+  // |service| is the candidate service to show the infobar for.
+  static void MaybeShowIntentInfoBar(InfoBarTabHelper* infobar_helper,
+                                     WebIntentsRegistry* registry,
+                                     const WebIntentServiceData& service);
+
  private:
   // The web intents registry to use. Weak pointer.
   WebIntentsRegistry* registry_;