[PageLoadMetrics] Record bytes usage per page

chrome/browser/page_load_metrics/page_load_tracker.h

 // 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.
 
 #ifndef CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_TRACKER_H_
 #define CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_TRACKER_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 134 matching lines @@
   // killed at any time after this method is invoked without further
   // notification.
   void FlushMetricsOnAppEnterBackground();
 
   void NotifyClientRedirectTo(const PageLoadTracker& destination);
 
   // Returns true if the timing was successfully updated.
   bool UpdateTiming(const PageLoadTiming& timing,
                     const PageLoadMetadata& metadata);
 
-  void OnLoadedSubresource(bool was_cached);
+  void OnLoadedResource(bool was_cached, int64_t raw_body_bytes);
 
   // Signals that we should stop tracking metrics for the associated page load.
   // We may stop tracking a page load if it doesn't meet the criteria for
   // tracking metrics in DidFinishNavigation.
   void StopTracking();
 
   int aborted_chain_size() const { return aborted_chain_size_; }
   int aborted_chain_size_same_url() const {
     return aborted_chain_size_same_url_;
   }
@@ skipping 112 matching lines @@
   PageLoadMetadata metadata_;
 
   ui::PageTransition page_transition_;
 
   // Note: these are only approximations, based on WebContents attribution from
   // ResourceRequestInfo objects while this is the currently committed load in
   // the WebContents.
   int num_cache_requests_;
   int num_network_requests_;
 
+  // The number of body (not header) prefilter bytes consumed by requests for
+  // the page.
+  int64_t cache_bytes_;
+  int64_t network_bytes_;
+
   // Whether this page load was user initiated.
   UserInitiatedInfo user_initiated_info_;
 
   // This is a subtle member. If a provisional load A gets aborted by
   // provisional load B, which gets aborted by C that eventually commits, then
   // there exists an abort chain of length 2, starting at A's navigation_start.
   // This is useful because it allows histograming abort chain lengths based on
   // what the last load's transition type is. i.e. holding down F-5 to spam
   // reload will produce a long chain with the RELOAD transition.
   const int aborted_chain_size_;
 
   // This member counts consecutive provisional aborts that share a url. It will
   // always be less than or equal to |aborted_chain_size_|.
   const int aborted_chain_size_same_url_;
 
   // Interface to chrome features. Must outlive the class.
   PageLoadMetricsEmbedderInterface* const embedder_interface_;
 
   std::vector<std::unique_ptr<PageLoadMetricsObserver>> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(PageLoadTracker);
 };
 
 }  // namespace page_load_metrics
 
 #endif  // CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_TRACKER_H_