[PageLoadMetrics] Record bytes usage per page

chrome/browser/page_load_metrics/page_load_metrics_observer.h

 // Copyright 2015 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_METRICS_OBSERVER_H_
 #define CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_METRICS_OBSERVER_H_
 
 #include "base/macros.h"
 #include "base/optional.h"
 #include "chrome/common/page_load_metrics/page_load_timing.h"
@@ skipping 100 matching lines @@
       const base::Optional<base::TimeDelta>& first_foreground_time,
       bool started_in_foreground,
       UserInitiatedInfo user_initiated_info,
       const GURL& committed_url,
       const GURL& start_url,
       UserAbortType abort_type,
       UserInitiatedInfo abort_user_initiated_info,
       const base::Optional<base::TimeDelta>& time_to_abort,
       int num_cache_requests,
       int num_network_requests,
+      int64_t cache_bytes,
+      int64_t net_bytes,
       const PageLoadMetadata& metadata);
 
   PageLoadExtraInfo(const PageLoadExtraInfo& other);
 
   ~PageLoadExtraInfo();
 
   // The first time that the page was backgrounded since the navigation started.
   const base::Optional<base::TimeDelta> first_background_time;
 
   // The first time that the page was foregrounded since the navigation started.
@@ skipping 30 matching lines @@
   UserInitiatedInfo abort_user_initiated_info;
 
   const base::Optional<base::TimeDelta> time_to_abort;
 
   // 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;
 
+  // Bytes consumed by this page.
+  int64_t cache_bytes;
+  int64_t network_bytes;

[Bryan McQuade, 2016/12/16 14:28:45]

i think it's implicit, but just to be extra clear, can you add a comment to
explain that this is HTTP bytes on the wire, excluding HTTP headers? e.g. it's
the gzipped size of a response, rather than the post-ungzip size?

Is the same true for cache bytes? Both network and cache bytes are "wire sizes",
less HTTP headers?

[jkarlin, 2016/12/19 19:26:01]

Done.

+
   // Extra information supplied to the page load metrics system from the
   // renderer.
   const PageLoadMetadata metadata;
 };
 
 // Interface for PageLoadMetrics observers. All instances of this class are
 // owned by the PageLoadTracker tracking a page load.
 class PageLoadMetricsObserver {
  public:
   // ObservePolicy is used as a return value on some PageLoadMetricsObserver
@@ skipping 124 matching lines @@
   // OnFailedProvisionalLoad is invoked for tracked page loads that did not
   // commit, immediately before the observer is deleted.
   virtual void OnFailedProvisionalLoad(
       const FailedProvisionalLoadInfo& failed_provisional_load_info,
       const PageLoadExtraInfo& extra_info) {}
 };
 
 }  // namespace page_load_metrics
 
 #endif  // CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_METRICS_OBSERVER_H_