Associate a main resource request with its PageLoadTracker.

chrome/browser/page_load_metrics/metrics_web_contents_observer.h

Index: chrome/browser/page_load_metrics/metrics_web_contents_observer.h
diff --git a/chrome/browser/page_load_metrics/metrics_web_contents_observer.h b/chrome/browser/page_load_metrics/metrics_web_contents_observer.h
index f8158ba85230ec3861a13484e368a1c1ed9dd324..3a9e0b97871f45faf37558c6ae6f665cdbc1d71b 100644
--- a/chrome/browser/page_load_metrics/metrics_web_contents_observer.h
+++ b/chrome/browser/page_load_metrics/metrics_web_contents_observer.h
@@ -54,6 +54,8 @@ class MetricsWebContentsObserver
   // content::WebContentsObserver implementation:
   bool OnMessageReceived(const IPC::Message& message,
                          content::RenderFrameHost* render_frame_host) override;
+  void ReadyToCommitNavigation(
+      content::NavigationHandle* navigation_handle) override;
   void DidFinishNavigation(
       content::NavigationHandle* navigation_handle) override;
   void DidRedirectNavigation(
@@ -69,8 +71,10 @@ class MetricsWebContentsObserver
   // This method is forwarded from the MetricsNavigationThrottle.
   void WillStartNavigationRequest(content::NavigationHandle* navigation_handle);
 
-  // A resource request completed on the IO thread.
-  void OnRequestComplete(content::ResourceType resource_type,
+  // A resource request completed on the IO thread. This method is invoked on
+  // the UI thread.
+  void OnRequestComplete(const content::GlobalRequestID& request_id,

[Charlie Harrison, 2017/01/13 15:56:23]

#include "content/public/browser/global_request_id.h"

+                         content::ResourceType resource_type,
                          bool was_cached,
                          bool used_data_reduction_proxy,
                          int64_t raw_body_bytes,
@@ -97,6 +101,14 @@ class MetricsWebContentsObserver
       content::NavigationHandle* navigation_handle,
       std::unique_ptr<PageLoadTracker> tracker);
 
+  // Return a PageLoadTracker (either provisional or committed) that matches the
+  // given request attributes, or nullptr if there are no matching
+  // PageLoadTrackers.
+  PageLoadTracker* GetTrackerOrNullForRequest(
+      const content::GlobalRequestID& request_id,
+      content::ResourceType resource_type,
+      base::TimeTicks creation_time);
+
   // Notify all loads, provisional and committed, that we performed an action
   // that might abort them.
   void NotifyAbortAllLoads(UserAbortType abort_type,