[subresource_filter] Add metrics for all NavigationThrottle delays

components/subresource_filter/content/browser/subframe_navigation_filtering_throttle.h

 // Copyright 2017 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 COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_SUBFRAME_NAVIGATION_FILTERING_THROTTLE_H_
 #define COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_SUBFRAME_NAVIGATION_FILTERING_THROTTLE_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
 #include "components/subresource_filter/content/browser/async_document_subresource_filter.h"
 #include "content/public/browser/navigation_throttle.h"
 
 namespace content {
 class NavigationHandle;
 }  // namespace content
 
 namespace subresource_filter {
 
 class AsyncDocumentSubresourceFilter;
@@ skipping 19 matching lines @@
       override;
   const char* GetNameForLogging() override;
 
  private:
   content::NavigationThrottle::ThrottleCheckResult DeferToCalculateLoadPolicy();
   void OnCalculatedLoadPolicy(LoadPolicy policy);
 
   // Must outlive this class.
   AsyncDocumentSubresourceFilter* parent_frame_filter_;
 
+  base::TimeTicks last_defer_time_;

[shivanisha, 2017/05/05 18:44:50]

nit: Rename to defer_start_timestamp_ to emphasize it is actually a timestamp?

[Charlie Harrison, 2017/05/05 18:56:07]

What about last_defer_timestamp_? Since we defer not only at the start but also
during redirects.

+  base::TimeDelta total_defer_time_;
+  bool disallowed_ = false;
+
   base::WeakPtrFactory<SubframeNavigationFilteringThrottle> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SubframeNavigationFilteringThrottle);
 };
 
 }  // namespace subresource_filter
 
 #endif  // COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_SUBFRAME_NAVIGATION_FILTERING_THROTTLE_H_