Factor PageLoadTracker into its own header and impl files.

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 3d6daece59a17bb31c4fb1ed0d43619187a96c06..4a43b9d1beaa9f4bf33827f2b329be1e9ce5ab06 100644
--- a/chrome/browser/page_load_metrics/metrics_web_contents_observer.h
+++ b/chrome/browser/page_load_metrics/metrics_web_contents_observer.h
@@ -18,7 +18,6 @@
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 #include "content/public/common/resource_type.h"
-#include "net/base/net_errors.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 
 namespace content {
@@ -32,277 +31,9 @@ class Message;
 
 namespace page_load_metrics {
 
+class PageLoadMetricsEmbedderInterface;
 class PageLoadTracker;
 
-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[];
-
-}  // 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 {
-  // 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_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_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,
-
-  // Tracks frequency with which we record an abort time that occurred before
-  // navigation start. This is expected to happen in some cases (see comments in
-  // cc file for details). We use this error counter to understand how often it
-  // happens.
-  ERR_ABORT_BEFORE_NAVIGATION_START,
-
-  // A new navigation triggers abort updates in multiple trackers in
-  // |aborted_provisional_loads_|, when usually there should only be one (the
-  // navigation that just aborted because of this one). If this happens, the
-  // latest aborted load is used to track the chain size.
-  ERR_NAVIGATION_SIGNALS_MULIPLE_ABORTED_LOADS,
-
-  // Received user input without a relevant load. This error type is deprecated,
-  // as it is valid to receive user input without a relevant load. We leave the
-  // enum value here since it's also used in histogram recording, so it's
-  // important that we not re-use this enum entry for a different value.
-  DEPRECATED_ERR_USER_INPUT_WITH_NO_RELEVANT_LOAD,
-
-  // A TimeTicks value in the browser process has value less than
-  // navigation_start_. This could happen if navigation_start_ was computed in
-  // renderer process and the system clock has inter process time tick skew.
-  ERR_INTER_PROCESS_TIME_TICK_SKEW,
-
-  // At the time a PageLoadTracker was destroyed, we had received neither a
-  // commit nor a failed provisional load.
-  ERR_NO_COMMIT_OR_FAILED_PROVISIONAL_LOAD,
-
-  // 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 bool IsPrerendering(content::WebContents* web_contents) = 0;
-  virtual bool IsNewTabPageUrl(const GURL& url) = 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.
-// MetricsWebContentsObserver manages a set of provisional PageLoadTrackers, as
-// well as a committed PageLoadTracker.
-class PageLoadTracker {
- 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,
-                  int aborted_chain_size,
-                  int aborted_chain_size_same_url);
-  ~PageLoadTracker();
-  void Redirect(content::NavigationHandle* navigation_handle);
-  void Commit(content::NavigationHandle* navigation_handle);
-  void FailedProvisionalLoad(content::NavigationHandle* navigation_handle);
-  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);
-
-  // Returns true if the timing was successfully updated.
-  bool UpdateTiming(const PageLoadTiming& timing,
-                    const PageLoadMetadata& metadata);
-
-  void OnLoadedSubresource(bool was_cached);
-
-  // 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_;
-  }
-
-  UserAbortType abort_type() const { return abort_type_; }
-  base::TimeTicks abort_time() const { return abort_time_; }
-
-  void AddObserver(std::unique_ptr<PageLoadMetricsObserver> observer);
-
-  // If the user performs some abort-like action while we are tracking this page
-  // load, notify the tracker. Note that we may not classify this as an abort if
-  // we've already performed a first paint.
-  // is_certainly_browser_timestamp signifies if the timestamp passed is taken
-  // in the
-  // browser process or not. We need this to possibly clamp browser timestamp on
-  // a machine with inter process time tick skew.
-  void NotifyAbort(UserAbortType abort_type,
-                   bool user_initiated,
-                   base::TimeTicks timestamp,
-                   bool is_certainly_browser_timestamp);
-  void UpdateAbort(UserAbortType abort_type,
-                   bool user_initiated,
-                   base::TimeTicks timestamp,
-                   bool is_certainly_browser_timestamp);
-
-  // This method returns true if this page load has been aborted with type of
-  // ABORT_OTHER, and the |abort_cause_time| is within a sufficiently close
-  // delta to when it was aborted. Note that only provisional loads can be
-  // aborted with ABORT_OTHER. While this heuristic is coarse, it works better
-  // 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);
-
-  // Only valid to call post-commit.
-  const GURL& committed_url() const {
-    DCHECK(!committed_url_.is_empty());
-    return committed_url_;
-  }
-
-  base::TimeTicks navigation_start() const { return navigation_start_; }
-
-  PageLoadExtraInfo ComputePageLoadExtraInfo();
-
-  ui::PageTransition page_transition() const { return page_transition_; }
-
- private:
-  // 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 UpdateAbortInternal(UserAbortType abort_type,
-                           bool user_initiated,
-                           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);
-
-  // 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_;
-
-  // The navigation start in TimeTicks, not the wall time reported by Blink.
-  const base::TimeTicks navigation_start_;
-
-  // The committed URL of this page load.
-  GURL committed_url_;
-
-  // The start URL for this page load (before redirects).
-  GURL start_url_;
-
-  std::unique_ptr<FailedProvisionalLoadInfo> failed_provisional_load_info_;
-
-  // Will be ABORT_NONE if we have not aborted this load yet. Otherwise will
-  // be the first abort action the user performed.
-  UserAbortType abort_type_;
-
-  // This boolean is only an approximation. As the aborts pipeline is updated,
-  // more abort types will have this set to true. Currently, this is only set
-  // for navigations aborting navigations.
-  bool abort_user_initiated_;
-
-  base::TimeTicks abort_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 timing_;
-  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_;
-
-  // This is derived from the user gesture bit in the renderer. For browser
-  // initiated navigations this will always be true.
-  bool user_gesture_;
-
-  // 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);
-};
-
 // MetricsWebContentsObserver tracks page loads and loading metrics
 // related data based on IPC messages received from a
 // MetricsRenderFrameObserver.