Factor management of metrics updates into its own class.

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>
 
 #include "base/macros.h"
 #include "base/optional.h"
 #include "base/time/time.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_observer.h"
+#include "chrome/browser/page_load_metrics/page_load_metrics_update_dispatcher.h"
 #include "chrome/browser/page_load_metrics/user_input_tracker.h"
 #include "chrome/common/page_load_metrics/page_load_timing.h"
 #include "content/public/browser/global_request_id.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "ui/base/page_transition_types.h"
 
 class GURL;
 
 namespace blink {
 class WebInputEvent;
 }  // namespace blink
 
 namespace content {
 class NavigationHandle;
-class RenderFrameHost;
 }  // namespace content
 
 namespace page_load_metrics {
 
 class PageLoadMetricsEmbedderInterface;
 class PageLoadMetricsObserver;
 
 namespace internal {
 
 extern const char kErrorEvents[];
 extern const char kAbortChainSizeReload[];
 extern const char kAbortChainSizeForwardBack[];
 extern const char kAbortChainSizeNewNavigation[];
 extern const char kAbortChainSizeNoCommit[];
 extern const char kAbortChainSizeSameURL[];
 extern const char kPageLoadCompletedAfterAppBackground[];
-extern const char kPageLoadTimingStatus[];
-
-// Used to track the status of PageLoadTimings received from the render process.
-//
-// 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 PageLoadTimingStatus {
-  // The PageLoadTiming is valid (all data within the PageLoadTiming is
-  // consistent with expectations).
-  VALID,
-
-  // All remaining status codes are for invalid PageLoadTimings.
-
-  // The PageLoadTiming was empty.
-  INVALID_EMPTY_TIMING,
-
-  // The PageLoadTiming had a null navigation_start.
-  INVALID_NULL_NAVIGATION_START,
-
-  // Script load or execution durations in the PageLoadTiming were too long.
-  INVALID_SCRIPT_LOAD_LONGER_THAN_PARSE,
-  INVALID_SCRIPT_EXEC_LONGER_THAN_PARSE,
-  INVALID_SCRIPT_LOAD_DOC_WRITE_LONGER_THAN_SCRIPT_LOAD,
-  INVALID_SCRIPT_EXEC_DOC_WRITE_LONGER_THAN_SCRIPT_EXEC,
-
-  // The order of two events in the PageLoadTiming was invalid. Either the first
-  // wasn't present when the second was present, or the second was reported as
-  // happening before the first.
-  INVALID_ORDER_RESPONSE_START_PARSE_START,
-  INVALID_ORDER_PARSE_START_PARSE_STOP,
-  INVALID_ORDER_PARSE_STOP_DOM_CONTENT_LOADED,
-  INVALID_ORDER_DOM_CONTENT_LOADED_LOAD,
-  INVALID_ORDER_PARSE_START_FIRST_LAYOUT,
-  INVALID_ORDER_FIRST_LAYOUT_FIRST_PAINT,
-  INVALID_ORDER_FIRST_PAINT_FIRST_TEXT_PAINT,
-  INVALID_ORDER_FIRST_PAINT_FIRST_IMAGE_PAINT,
-  INVALID_ORDER_FIRST_PAINT_FIRST_CONTENTFUL_PAINT,
-  INVALID_ORDER_FIRST_PAINT_FIRST_MEANINGFUL_PAINT,
-
-  // New values should be added before this final entry.
-  LAST_PAGE_LOAD_TIMING_STATUS
-};
 
 }  // namespace internal
 
 // 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 {
@@ skipping 83 matching lines @@
 // to access them.
 void RecordInternalError(InternalErrorLoadEvent event);
 PageEndReason EndReasonForPageTransition(ui::PageTransition transition);
 void LogAbortChainSameURLHistogram(int aborted_chain_size_same_url);
 bool IsNavigationUserInitiated(content::NavigationHandle* handle);
 
 // This class tracks a given page load, starting from navigation start /
 // provisional load, until a new navigation commits or the navigation fails.
 // MetricsWebContentsObserver manages a set of provisional PageLoadTrackers, as
 // well as a committed PageLoadTracker.
-class PageLoadTracker {
+class PageLoadTracker : public PageLoadMetricsUpdateDispatcher::Client {
  public:
   // Caller must guarantee that the embedder_interface pointer outlives this
   // class. The PageLoadTracker must not hold on to
   // currently_committed_load_or_null or navigation_handle beyond the scope of
   // the constructor.
   PageLoadTracker(bool in_foreground,
                   PageLoadMetricsEmbedderInterface* embedder_interface,
                   const GURL& currently_committed_url,
                   content::NavigationHandle* navigation_handle,
                   UserInitiatedInfo user_initiated_info,
                   int aborted_chain_size,
                   int aborted_chain_size_same_url);
-  ~PageLoadTracker();
+  ~PageLoadTracker() override;
+
+  // PageLoadMetricsUpdateDispatcher::Client implementation:
+  void OnTimingChanged() override;
+  void OnMainFrameMetadataChanged() override;
+  void OnSubframeMetadataChanged() override;
+
   void Redirect(content::NavigationHandle* navigation_handle);
   void WillProcessNavigationResponse(
       content::NavigationHandle* navigation_handle);
   void Commit(content::NavigationHandle* navigation_handle);
   void DidCommitSameDocumentNavigation(
       content::NavigationHandle* navigation_handle);
   void DidFinishSubFrameNavigation(
       content::NavigationHandle* navigation_handle);
   void FailedProvisionalLoad(content::NavigationHandle* navigation_handle,
                              base::TimeTicks failed_load_time);
   void WebContentsHidden();
   void WebContentsShown();
 
   void OnInputEvent(const blink::WebInputEvent& event);
 
   // Flush any buffered metrics, as part of the metrics subsystem persisting
   // metrics as the application goes into the background. The application may be
   // killed at any time after this method is invoked without further
   // notification.
   void FlushMetricsOnAppEnterBackground();
 
   void NotifyClientRedirectTo(const PageLoadTracker& destination);
 
-  void UpdateTiming(const mojom::PageLoadTiming& timing,
-                    const mojom::PageLoadMetadata& metadata);
-
-  void UpdateSubFrameTiming(content::RenderFrameHost* render_frame_host,
-                            const mojom::PageLoadTiming& new_timing,
-                            const mojom::PageLoadMetadata& new_metadata);
-
-  // Update metadata for child frames. Updates for child frames arrive
-  // separately from updates for the main frame, so aren't included in
-  // UpdateTiming.
-  void UpdateSubFrameMetadata(const mojom::PageLoadMetadata& subframe_metadata);
-
   void OnStartedResource(
       const ExtraRequestStartInfo& extra_request_started_info);
 
   void OnLoadedResource(
       const ExtraRequestCompleteInfo& extra_request_complete_info);
 
   // 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();
@@ skipping 31 matching lines @@
   // and is simpler than other feasible methods. See https://goo.gl/WKRG98.
   bool IsLikelyProvisionalAbort(base::TimeTicks abort_cause_time) const;
 
   bool MatchesOriginalNavigation(content::NavigationHandle* navigation_handle);
 
   bool did_commit() const { return did_commit_; }
   const GURL& url() const { return url_; }
 
   base::TimeTicks navigation_start() const { return navigation_start_; }
 
-  PageLoadExtraInfo ComputePageLoadExtraInfo();
+  PageLoadExtraInfo ComputePageLoadExtraInfo() const;
 
   ui::PageTransition page_transition() const { return page_transition_; }
 
   UserInitiatedInfo user_initiated_info() const { return user_initiated_info_; }
 
   UserInputTracker* input_tracker() { return &input_tracker_; }
 
+  PageLoadMetricsUpdateDispatcher* metrics_update_dispatcher() {
+    return &metrics_update_dispatcher_;
+  }
+
   // Whether this PageLoadTracker has a navigation GlobalRequestID that matches
   // the given request_id. This method will return false before
   // WillProcessNavigationResponse has been invoked, as PageLoadTracker doesn't
   // know its GlobalRequestID until WillProcessNavigationResponse has been
   // invoked.
   bool HasMatchingNavigationRequestID(
       const content::GlobalRequestID& request_id) const;
 
   // Invoked when a media element starts playing.
   void MediaStartedPlaying(
       const content::WebContentsObserver::MediaPlayerInfo& video_type,
       bool is_in_main_frame);
 
   // Invoked on navigations where a navigation delay was added by the
   // DelayNavigationThrottle. This is a temporary method that will be removed
   // once the experiment is complete.
   void OnNavigationDelayComplete(base::TimeDelta scheduled_delay,
                                  base::TimeDelta actual_delay);
 
  private:
-  using FrameTreeNodeId = int;
-
   // This function converts a TimeTicks value taken in the browser process
   // to navigation_start_ if:
   // - base::TimeTicks is not comparable across processes because the clock
   // is not system wide monotonic.
   // - *event_time < navigation_start_
   void ClampBrowserTimestampIfInterProcessTimeTickSkew(
       base::TimeTicks* event_time);
 
   void UpdatePageEndInternal(PageEndReason page_end_reason,
                              UserInitiatedInfo user_initiated_info,
                              base::TimeTicks timestamp,
                              bool is_certainly_browser_timestamp);
 
   // If |final_navigation| is null, then this is an "unparented" abort chain,
   // and represents a sequence of provisional aborts that never ends with a
   // committed load.
   void LogAbortChainHistograms(content::NavigationHandle* final_navigation);
 
   void MaybeUpdateURL(content::NavigationHandle* navigation_handle);
 
-  // Merge values from |new_paint_timing| into |merged_page_timing_|, offsetting
-  // any new timings by the |navigation_start_offset|.
-  void MergePaintTiming(base::TimeDelta navigation_start_offset,
-                        const mojom::PaintTiming& new_paint_timing,
-                        bool is_main_frame);
-
-  void DispatchTimingUpdates();
-
   UserInputTracker input_tracker_;
 
   // Whether we stopped tracking this navigation after it was initiated. We may
   // stop tracking a navigation if it doesn't meet the criteria for tracking
   // metrics in DidFinishNavigation.
   bool did_stop_tracking_;
 
   // Whether the application went into the background when this PageLoadTracker
   // was active. This is a temporary boolean for UMA tracking.
   bool app_entered_background_;
@@ skipping 29 matching lines @@
 
   base::TimeTicks page_end_time_;
 
   // 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 for the currently tracked page. The fields in |paint_timing|
-  // are merged across all frames in the document. All other fields are for the
-  // main frame document.
-  mojom::PageLoadTimingPtr merged_page_timing_;
   mojom::PageLoadTimingPtr last_dispatched_merged_page_timing_;
 
-  mojom::PageLoadMetadata main_frame_metadata_;
-  mojom::PageLoadMetadataPtr last_dispatched_main_frame_metadata_;
-
-  mojom::PageLoadMetadata subframe_metadata_;
-
   ui::PageTransition page_transition_;
 
   base::Optional<content::GlobalRequestID> navigation_request_id_;
 
   // 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_;
 
-  // Navigation start offsets for the most recently committed document in each
-  // frame.
-  std::map<FrameTreeNodeId, base::TimeDelta> subframe_navigation_start_offset_;
+  PageLoadMetricsUpdateDispatcher metrics_update_dispatcher_;
 
   DISALLOW_COPY_AND_ASSIGN(PageLoadTracker);
 };
 
 }  // namespace page_load_metrics
 
 #endif  // CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_TRACKER_H_