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

chrome/browser/intents/register_intent_handler_infobar_delegate.cc

Index: chrome/browser/intents/register_intent_handler_infobar_delegate.cc
diff --git a/chrome/browser/intents/register_intent_handler_infobar_delegate.cc b/chrome/browser/intents/register_intent_handler_infobar_delegate.cc
index 4c711e4c95e4a25b67708cf772a0bb007062dca7..2727cfc9e4cbc33df2c67af596454660bdcb9c97 100644
--- a/chrome/browser/intents/register_intent_handler_infobar_delegate.cc
+++ b/chrome/browser/intents/register_intent_handler_infobar_delegate.cc
@@ -6,6 +6,7 @@
 
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
+#include "chrome/browser/infobars/infobar_tab_helper.h"
 #include "chrome/browser/intents/web_intents_registry.h"
 #include "chrome/browser/intents/web_intents_registry_factory.h"
 #include "chrome/browser/profiles/profile.h"
@@ -60,3 +61,51 @@ bool RegisterIntentHandlerInfoBarDelegate::LinkClicked(
   // TODO(jhawkins): Add associated bug for the article here.
   return false;
 }
+
+// A trampoline for showing the infobar if it is not already registered.
+// Triggered by a return to a query to the WebIntentsRegistry.
+class IntentCheckConsumer : public WebIntentsRegistry::Consumer {

[James Hawkins, 2011/10/05 18:37:12]

Add a method to WebIntentsRegistry to check for the existence of an intent
registration.

[Greg Billock, 2011/10/05 22:19:02]

Done.

+ public:
+  IntentCheckConsumer(InfoBarTabHelper* infobar_helper,
+                      WebIntentsRegistry* registry,
+                      const WebIntentServiceData& service)
+      : infobar_helper_(infobar_helper),
+        registry_(registry),
+        service_(service) {}
+  virtual ~IntentCheckConsumer() {}
+
+  // Gets the list of all intents for a particular action. We'll check them all
+  // to see if this one is already registered. If it is, we bail out without
+  // showing the infobar. If it isn't, we show the infobar. We then delete
+  // ourselves.
+  virtual void OnIntentsQueryDone(
+      WebIntentsRegistry::QueryID id,
+      const WebIntentsRegistry::IntentList& list) OVERRIDE {
+    scoped_ptr<IntentCheckConsumer> self_deleter(this);
+
+    for (WebIntentsRegistry::IntentList::const_iterator i = list.begin();
+         i != list.end(); ++i) {
+      if (*i == service_)
+        return;
+    }
+
+    infobar_helper_->AddInfoBar(new RegisterIntentHandlerInfoBarDelegate(
+        infobar_helper_, registry_, service_));
+  }
+
+ private:
+  InfoBarTabHelper* infobar_helper_;
+  WebIntentsRegistry* registry_;
+  WebIntentServiceData service_;
+};
+
+// static
+void RegisterIntentHandlerInfoBarDelegate::MaybeShowIntentInfoBar(
+    InfoBarTabHelper* infobar_helper,
+    WebIntentsRegistry* registry,
+    const WebIntentServiceData& service) {
+  registry->GetIntentProviders(service.action,
+                               new IntentCheckConsumer(infobar_helper,
+                                                       registry,
+                                                       service));
+}