Autoplay experiment metric fixes and additions.

third_party/WebKit/Source/core/html/AutoplayExperimentHelper.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 AutoplayExperimentHelper_h
 #define AutoplayExperimentHelper_h
 
 #include "core/page/Page.h"
 #include "platform/Timer.h"
 #include "platform/geometry/IntRect.h"
@@ skipping 44 matching lines @@
 
     // play() failed to play due to gesture requirement.
     PlayMethodFailed = 10,
 
     // Some play, whether user initiated or not, started.
     AnyPlaybackStarted = 11,
     // Some play, whether user initiated or not, paused.
     AnyPlaybackPaused = 12,
     // Some playback, whether user initiated or not, bailed out early.
     AnyPlaybackBailout = 13,
+    // Some playback, whether user initiated or not, played to completion.
+    AnyPlaybackComplete = 14,
+
+    // Number of audio elements detected.

[philipj_slow, 2015/11/26 15:30:56]

Clarify that this is only elements that reached the resource fetch algorithm?

[liberato (no reviews please), 2015/12/02 00:58:08]

Done.

+    AnyAudioElement = 15,
+    // Numer of video elements detected.
+    AnyVideoElement = 16,
+
+    // User gesture was bypassed, and playback started, and media played to
+    // completion without a user-initiated pause.
+    AutoplayComplete = 17,
+
+    // Autoplay started after the gesture requirement was removed by a
+    // user gesture load().
+    GesturelessPlaybackEnabledByLoad = 18,
+
+    // Gestureless playback started after the gesture requirement was removed
+    // because src is media stream.
+    GesturelessPlaybackEnabledByStream = 19,
+
+    // Gestureless playback was started, but it is unknown why a user gesture
+    // was not required.  This includes the case where none is ever required.
+    GesturelessPlaybackUnknownReason = 20,
 
     // This enum value must be last.
     NumberOfAutoplayMetrics,
 };
 
 class AutoplayExperimentHelper final {
     DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
 public:
     explicit AutoplayExperimentHelper(HTMLMediaElement&);
     ~AutoplayExperimentHelper();
@@ skipping 55 matching lines @@
     // requires it, else do nothing.
     void muteIfNeeded();
 
     // Maybe override the requirement for a user gesture, and start playing
     // autoplay media.  Returns true if only if it starts playback.
     bool maybeStartPlaying();
 
     // Configure internal state to record that the autoplay experiment is
     // going to start playback.  This doesn't actually start playback, since
     // there are several different cases.
-    void prepareToPlay(AutoplayMetrics);
+    void prepareToAutoplay(AutoplayMetrics);
 
     // Process a timer for checking visibility.
     void viewportTimerFired(Timer<AutoplayExperimentHelper>*);
 
     // Return our media element's document.
     Document& document() const;
 
     HTMLMediaElement& element() const;
 
     inline bool enabled(Mode mode) const
@@ skipping 31 matching lines @@
     const AutoplayExperimentHelper::Mode& b)
 {
     a = static_cast<AutoplayExperimentHelper::Mode>(static_cast<int>(a) | static_cast<int>(b));
     return a;
 }
 
 
 } // namespace blink
 
 #endif // AutoplayExperimentHelper_h