Fix the handling of user gestures for external protocol handler dialogs.

chrome/browser/autocomplete/autocomplete_input.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/autocomplete/autocomplete_input.h"
 
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/external_protocol/external_protocol_handler.h"
 #include "chrome/browser/profiles/profile_io_data.h"
@@ skipping 180 matching lines @@
         LowerCaseEqualsASCII(parsed_scheme, content::kJavaScriptScheme) ||
         LowerCaseEqualsASCII(parsed_scheme, content::kDataScheme))
       return return_value_for_non_http_url;
 
     // Not an internal protocol.  Check and see if the user has explicitly
     // opened this scheme as a URL before, or if the "scheme" is actually a
     // username.  We need to do this after the check above because some
     // handlable schemes (e.g. "javascript") may be treated as "blocked" by the
     // external protocol handler because we don't want pages to open them, but
     // users still can.
+    // External protocol handler checks for the existence of a user gesture.
+    // Fake one so that we don't always get a BLOCK result.

[Peter Kasting, 2014/03/28 22:56:37]

Nit: How about this comment, appended at the end of the previous paragraph:

Note that the protocol handler needs to be informed that omnibox input should
always be considered "user gesture-triggered", lest it always return BLOCK.

[meacer, 2014/03/28 23:13:57]

Done.

+    ExternalProtocolHandler::ScopedUserGesture skip_user_gesture_check;
     ExternalProtocolHandler::BlockState block_state =
         ExternalProtocolHandler::GetBlockState(
             base::UTF16ToUTF8(parsed_scheme));
     switch (block_state) {
       case ExternalProtocolHandler::DONT_BLOCK:
         return return_value_for_non_http_url;
 
       case ExternalProtocolHandler::BLOCK:
         // If we don't want the user to open the URL, don't let it be navigated
         // to at all.
@@ skipping 319 matching lines @@
   current_page_classification_ = AutocompleteInput::INVALID_SPEC;
   type_ = INVALID;
   parts_ = url_parse::Parsed();
   scheme_.clear();
   canonicalized_url_ = GURL();
   prevent_inline_autocomplete_ = false;
   prefer_keyword_ = false;
   allow_exact_keyword_match_ = false;
   matches_requested_ = ALL_MATCHES;
 }