PageLoadMetricsObservers observe individual page loads

components/page_load_metrics/browser/metrics_web_contents_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 COMPONENTS_PAGE_LOAD_METRICS_BROWSER_PAGE_LOAD_METRICS_WEB_CONTENTS_OBSERVER_H_
 #define COMPONENTS_PAGE_LOAD_METRICS_BROWSER_PAGE_LOAD_METRICS_WEB_CONTENTS_OBSERVER_H_
 
 #include <map>
 
 #include "base/macros.h"
@@ skipping 16 matching lines @@
 namespace IPC {
 class Message;
 }  // namespace IPC
 
 namespace rappor {
 class RapporService;
 }
 
 namespace page_load_metrics {
 
+class PageLoadTracker;
+
 // These constants are for keeping the tests in sync.
 const char kHistogramFirstLayout[] = "PageLoad.Timing2.NavigationToFirstLayout";
 const char kHistogramFirstTextPaint[] =
     "PageLoad.Timing2.NavigationToFirstTextPaint";
 const char kHistogramDomContentLoaded[] =
     "PageLoad.Timing2.NavigationToDOMContentLoadedEventFired";
 const char kHistogramLoad[] = "PageLoad.Timing2.NavigationToLoadEventFired";
 const char kHistogramFirstPaint[] = "PageLoad.Timing2.NavigationToFirstPaint";
 const char kHistogramFirstImagePaint[] =
     "PageLoad.Timing2.NavigationToFirstImagePaint";
@@ skipping 63 matching lines @@
   // This event captures all the other ways a provisional load can fail.
   PROVISIONAL_LOAD_ERR_FAILED_NON_ABORT,
 
   // Counts the number of successful commits.
   PROVISIONAL_LOAD_COMMITTED,
 
   // Add values before this final count.
   PROVISIONAL_LOAD_LAST_ENTRY
 };
 
-// CommittedLoadEvents are events that occur on committed loads that we track.
-// Note that we capture events only for committed loads that:
+// CommittedRelevantLoadEvents are events that occur on committed loads that the
+// MetricsWebContentsObserver tracks. Note events are only captured for
+// committed loads that:
 //  - Are http/https.
 //  - Not same-page navigations.
 //  - Are not navigations to an error page.
 // We only know these things about a navigation post-commit.
 //
 // If you add elements to this enum, make sure you update the enum
 // value in histograms.xml. Only add elements to the end to prevent
 // inconsistencies between versions.
-enum CommittedLoadEvent {
-  // When a load that eventually commits started. Note we can't log this until
-  // commit time, but it represents when the actual page load started. Thus, we
-  // only separate this into .Background when a page load starts backgrounded.
-  COMMITTED_LOAD_STARTED,
+enum CommittedRelevantLoadEvent {
+  // When a load that eventually commits started. This cannot be logged until
+  // commit time, but it represents when the actual page load started. Thus, it
+  // only separates into .Background when a page load starts backgrounded.
+  RELEVANT_LOAD_STARTED,
 
   // These two events are disjoint. Sum them to find the total number of
-  // committed loads that we end up tracking.
-  COMMITTED_LOAD_FAILED_BEFORE_FIRST_LAYOUT,
-  COMMITTED_LOAD_SUCCESSFUL_FIRST_LAYOUT,
+  // committed loads that are tracked.
+  RELEVANT_LOAD_FAILED_BEFORE_FIRST_LAYOUT,
+  RELEVANT_LOAD_SUCCESSFUL_FIRST_LAYOUT,
 
   // TODO(csharrison) once first paint metrics are in place, add new events.
 
   // Add values before this final count.
-  COMMITTED_LOAD_LAST_ENTRY
+  RELEVANT_LOAD_LAST_ENTRY
 };
 
 // These errors are internal to the page_load_metrics subsystem and do not
 // reflect actual errors that occur during a page load.
 //
 // If you add elements to this enum, make sure you update the enum
 // value in histograms.xml. Only add elements to the end to prevent
 // inconsistencies between versions.
 enum InternalErrorLoadEvent {
   // A timing IPC was sent from the renderer that did not line up with previous
   // data we've received (i.e. navigation start is different or the timing
   // struct is somehow invalid). This error can only occur once the IPC is
   // vetted in other ways (see other errors).
   ERR_BAD_TIMING_IPC,
 
   // The following IPCs are not mutually exclusive.
   //
   // We received an IPC when we weren't tracking a committed load. This will
   // often happen if we get an IPC from a bad URL scheme (that is, the renderer
   // sent us an IPC from a navigation we don't care about).
-  ERR_IPC_WITH_NO_COMMITTED_LOAD,
+  ERR_IPC_WITH_NO_RELEVANT_LOAD,
 
   // Received a notification from a frame that has been navigated away from.
   ERR_IPC_FROM_WRONG_FRAME,
 
   // We received an IPC even through the last committed url from the browser
   // was not http/s. This can happen with the renderer sending IPCs for the
   // new tab page. This will often come paired with
-  // ERR_IPC_WITH_NO_COMMITTED_LOAD.
+  // ERR_IPC_WITH_NO_RELEVANT_LOAD.
   ERR_IPC_FROM_BAD_URL_SCHEME,
 
   // If we track a navigation, but the renderer sends us no IPCs. This could
   // occur if the browser filters loads less aggressively than the renderer.
   ERR_NO_IPCS_RECEIVED,
 
   // Add values before this final count.
   ERR_LAST_ENTRY
 };
 
 // This class serves as a functional interface to various chrome// features.
 // Impl version is defined in chrome/browser/page_load_metrics.
 class PageLoadMetricsEmbedderInterface {
  public:
   virtual ~PageLoadMetricsEmbedderInterface() {}
   virtual rappor::RapporService* GetRapporService() = 0;
   virtual bool IsPrerendering(content::WebContents* web_contents) = 0;
+  virtual void RegisterObservers(PageLoadTracker* metrics) = 0;
 };
 
 // This class tracks a given page load, starting from navigation start /
 // provisional load, until a new navigation commits or the navigation fails. It
 // also records RAPPOR/UMA about the page load.
 // MetricsWebContentsObserver manages a set of provisional PageLoadTrackers, as
 // well as a committed PageLoadTracker.
 class PageLoadTracker {
  public:
-  // Caller must guarantee that the observers and embedder_interface pointers
-  // outlives this class.
+  // Caller must guarantee that the embedder_interface pointers outlives this

[Randy Smith (Not in Mondays), 2015/12/03 01:20:42]

nit: pointer (singular).

+  // class.
   PageLoadTracker(bool in_foreground,
                   PageLoadMetricsEmbedderInterface* embedder_interface,
-                  content::NavigationHandle* navigation_handle,
-                  base::ObserverList<PageLoadMetricsObserver, true>* observers);
+                  content::NavigationHandle* navigation_handle);
   ~PageLoadTracker();
   void Redirect(content::NavigationHandle* navigation_handle);
   void Commit(content::NavigationHandle* navigation_handle);
   void WebContentsHidden();
   void WebContentsShown();
 
   // Returns true if the timing was successfully updated.
   bool UpdateTiming(const PageLoadTiming& timing);
   void RecordProvisionalEvent(ProvisionalLoadEvent event);
-  void RecordCommittedEvent(CommittedLoadEvent event, bool backgrounded);
+  void RecordCommittedEvent(CommittedRelevantLoadEvent event,
+                            bool backgrounded);
   bool HasBackgrounded();
 
+  void set_renderer_tracked(bool renderer_tracked);
+  bool renderer_tracked() { return renderer_tracked_; }
+
+  void AddObserver(scoped_ptr<PageLoadMetricsObserver> observer);
+
  private:
   PageLoadExtraInfo GetPageLoadMetricsInfo();
   // Only valid to call post-commit.
-  const GURL& GetCommittedURL();
+  const GURL& committed_url();
 
   base::TimeDelta GetBackgroundDelta();
   void RecordTimingHistograms();
   void RecordRappor();
 
+  // Whether the renderer should be sending timing IPCs to this page load.
+  bool renderer_tracked_;
+
   bool has_commit_;
 
   // The navigation start in TimeTicks, not the wall time reported by Blink.
   const base::TimeTicks navigation_start_;
 
   // We record separate metrics for events that occur after a background,
   // because metrics like layout/paint are delayed artificially
   // when they occur in the background.
   base::TimeTicks background_time_;
   base::TimeTicks foreground_time_;
   bool started_in_foreground_;
 
   PageLoadTiming timing_;
   GURL url_;
 
   // Interface to chrome features. Must outlive the class.
   PageLoadMetricsEmbedderInterface* const embedder_interface_;
 
-  // List of observers. This must outlive the class.
-  base::ObserverList<PageLoadMetricsObserver, true>* observers_;
+  std::vector<scoped_ptr<PageLoadMetricsObserver>> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(PageLoadTracker);
 };
 
 // MetricsWebContentsObserver logs page load UMA metrics based on
 // IPC messages received from a MetricsRenderFrameObserver.
 class MetricsWebContentsObserver
     : public content::WebContentsObserver,
-      public content::WebContentsUserData<MetricsWebContentsObserver>,
-      public PageLoadMetricsObservable {
+      public content::WebContentsUserData<MetricsWebContentsObserver> {
  public:
   // Note that the returned metrics is owned by the web contents.
   // The caller must guarantee that the RapporService (if non-null) will
   // outlive the WebContents.
   static MetricsWebContentsObserver* CreateForWebContents(
       content::WebContents* web_contents,
       scoped_ptr<PageLoadMetricsEmbedderInterface> embedder_interface);
   MetricsWebContentsObserver(
       content::WebContents* web_contents,
       scoped_ptr<PageLoadMetricsEmbedderInterface> embedder_interface);
   ~MetricsWebContentsObserver() override;
 
-  void AddObserver(PageLoadMetricsObserver* observer) override;
-  void RemoveObserver(PageLoadMetricsObserver* observer) override;
-
   // content::WebContentsObserver implementation:
   bool OnMessageReceived(const IPC::Message& message,
                          content::RenderFrameHost* render_frame_host) override;
   void DidStartNavigation(
       content::NavigationHandle* navigation_handle) override;
   void DidFinishNavigation(
       content::NavigationHandle* navigation_handle) override;
   void DidRedirectNavigation(
       content::NavigationHandle* navigation_handle) override;
 
@@ skipping 12 matching lines @@
 
   // This map tracks all of the navigations ongoing that are not committed
   // yet. Once a navigation is committed, it moves from the map to
   // committed_load_. Note that a PageLoadTrackers NavigationHandle is only
   // valid until commit time, when we remove it from the map.
   std::map<content::NavigationHandle*, scoped_ptr<PageLoadTracker>>
       provisional_loads_;
   scoped_ptr<PageLoadTracker> committed_load_;
 
   scoped_ptr<PageLoadMetricsEmbedderInterface> embedder_interface_;
-  base::ObserverList<PageLoadMetricsObserver, true> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(MetricsWebContentsObserver);
 };
 
 }  // namespace page_load_metrics
 
 #endif  // COMPONENTS_PAGE_LOAD_METRICS_BROWSER_PAGE_LOAD_METRICS_WEB_CONTENTS_OBSERVER_H_