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 21bc4de073089e40b5da40a1b04f101a1f4c475a..91ab2b3be3012a0c86ab839b5b2b915586386a67 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;
 
@@ -31,6 +32,17 @@ class RegisterIntentHandlerInfoBarDelegate : public ConfirmInfoBarDelegate {
   virtual string16 GetLinkText() const OVERRIDE;
   virtual bool LinkClicked(WindowOpenDisposition disposition) OVERRIDE;
 
+  // Shows the intent registration infobar if |service| has not already been
+  // registered. Else no-op.

[James Hawkins, 2011/11/09 17:32:42]

Grammar police: Sentence fragment; it's clear the former only happens if the
condition is met, so I'd say it's OK to remove this part of the comment.

[Greg Billock, 2011/11/10 00:21:31]

Done.

+  // |infobar_helper| is the infobar controller for the tab in which the infobar
+  // may be shown. Must not be null.

[James Hawkins, 2011/11/09 17:32:42]

nit: s/null/NULL/ here and elsewhere.

[Greg Billock, 2011/11/10 00:21:31]

Done.

+  // |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 webkit_glue::WebIntentServiceData& service);
+
  private:
   // The web intents registry to use. Weak pointer.
   WebIntentsRegistry* registry_;