Open external application dialog should not show for Chrome.

chrome/browser/external_protocol/external_protocol_handler.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTERNAL_PROTOCOL_EXTERNAL_PROTOCOL_HANDLER_H_
 #define CHROME_BROWSER_EXTERNAL_PROTOCOL_EXTERNAL_PROTOCOL_HANDLER_H_
 #pragma once
 
 #include <string>
 
+#include "chrome/browser/shell_integration.h"
+
 class GURL;
 class PrefService;
 
 namespace base {
 class DictionaryValue;
 }
 
 class ExternalProtocolHandler {
  public:
   enum BlockState {
     DONT_BLOCK,
     BLOCK,
     UNKNOWN,
   };
 
+  // Delegate to allow unit testing to provide different behavior.
+  class Delegate {
+   public:
+    virtual ShellIntegration::DefaultProtocolClientWorker* CreateShellWorker(
+        ShellIntegration::DefaultWebClientObserver* observer,
+        const std::string& protocol) = 0;
+    virtual BlockState GetBlockState(const std::string& scheme) = 0;
+    virtual void BlockRequest() = 0;
+    virtual void RunExternalProtocolDialog(const GURL& url,
+                                           int render_process_host_id,
+                                           int routing_id) = 0;
+    virtual void LaunchUrlWithoutSecurityCheck(const GURL& url) = 0;
+    virtual void FinishedProcessingCheck() = 0;
+    virtual ~Delegate() {}
+  };
+
   // Returns whether we should block a given scheme.
   static BlockState GetBlockState(const std::string& scheme);
 
   // Sets whether we should block a given scheme.
   static void SetBlockState(const std::string& scheme, BlockState state);
 
   // Checks to see if the protocol is allowed, if it is whitelisted,
   // the application associated with the protocol is launched on the io thread,
   // if it is blacklisted, returns silently. Otherwise, an
   // ExternalProtocolDialog is created asking the user. If the user accepts,
   // LaunchUrlWithoutSecurityCheck is called on the io thread and the
   // application is launched.
   // Must run on the UI thread.
   static void LaunchUrl(const GURL& url, int render_process_host_id,
-                        int tab_contents_id);
+                        int tab_contents_id) {
+      LaunchUrlWithDelegate(url, render_process_host_id, tab_contents_id, NULL);
+  }
+
+  // Version of LaunchUrl allowing use of a delegate to facilitate unit
+  // testing.
+  static void LaunchUrlWithDelegate(const GURL& url, int render_process_host_id,
+                                    int tab_contents_id, Delegate* delegate);
 
   // Creates and runs a External Protocol dialog box.
   // |url| - The url of the request.
   // |render_process_host_id| and |routing_id| are used by
   // tab_util::GetTabContentsByID to aquire the tab contents associated with
   // this dialog.
   // NOTE: There is a race between the Time of Check and the Time Of Use for
   //       the command line. Since the caller (web page) does not have access
   //       to change the command line by itself, we do not do anything special
   //       to protect against this scenario.
@@ skipping 21 matching lines @@
   static void PrepopulateDictionary(base::DictionaryValue* win_pref);
 
   // Allows LaunchUrl to proceed with launching an external protocol handler.
   // This is typically triggered by a user gesture, but is also called for
   // each extension API function. Note that each call to LaunchUrl resets
   // the state to false (not allowed).
   static void PermitLaunchUrl();
 };
 
 #endif  // CHROME_BROWSER_EXTERNAL_PROTOCOL_EXTERNAL_PROTOCOL_HANDLER_H_