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

chrome/browser/plugins/flash_download_interception.cc

Index: chrome/browser/plugins/flash_download_interception.cc
diff --git a/chrome/browser/plugins/flash_download_interception.cc b/chrome/browser/plugins/flash_download_interception.cc
index c3181421e70f6611dbd2e06592d729eb5f223d46..3ec89f7246bff7b50d489b6ec11e23312f8cb182 100644
--- a/chrome/browser/plugins/flash_download_interception.cc
+++ b/chrome/browser/plugins/flash_download_interception.cc
@@ -135,9 +135,9 @@ FlashDownloadInterception::MaybeCreateThrottleFor(NavigationHandle* handle) {
       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;
   }