make NavigationGesture part of public content API and use it outside content

chrome/browser/plugins/flash_download_interception.cc

 // Copyright 2016 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/plugins/flash_download_interception.h"
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/browser/content_settings/tab_specific_content_settings.h"
@@ skipping 117 matching lines @@
   // The source URL may be empty, it's a new tab. Intercepting that navigation
   // would lead to a blank new tab, which would be bad.
   GURL source_url = handle->GetWebContents()->GetLastCommittedURL();
   if (source_url.is_empty())
     return nullptr;
 
   Profile* profile = Profile::FromBrowserContext(
       handle->GetWebContents()->GetBrowserContext());
   HostContentSettingsMap* host_content_settings_map =
       HostContentSettingsMapFactory::GetForProfile(profile);
-  if (!ShouldStopFlashDownloadAction(host_content_settings_map, source_url,
-                                     handle->GetURL(),
-                                     handle->HasUserGesture())) {
+  if (!ShouldStopFlashDownloadAction(
+          host_content_settings_map, source_url, handle->GetURL(),
+          handle->GetNavigationGesture() == content::NavigationGestureUser)) {
     return nullptr;
   }
 
   return base::MakeUnique<navigation_interception::InterceptNavigationThrottle>(
       handle, base::Bind(&InterceptNavigation, source_url), true);
 }