Media Controls: move timeline related code to modules.

third_party/WebKit/Source/core/html/shadow/MediaControlTimelineMetrics.h

-// Copyright 2017 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 MediaControlTimelineMetrics_h
-#define MediaControlTimelineMetrics_h
-
-#include "platform/Histogram.h"
-#include "platform/wtf/Time.h"
-#include "public/platform/modules/screen_orientation/WebScreenOrientationType.h"
-
-namespace blink {
-
-// Helpers for tracking and reporting media control timeline metrics to UMA.
-class MediaControlTimelineMetrics {
- public:
-  // Start tracking a pointer gesture. |fromThumb| indicates whether the user
-  // started dragging from the thumb, as opposed to pressing down their pointer
-  // on some other part of the timeline track (causing time to jump).
-  void StartGesture(bool from_thumb);
-  // Finish tracking and report a pointer gesture.
-  void RecordEndGesture(int timeline_width, double media_duration_seconds);
-
-  // Start tracking a keydown. Ok to call multiple times if key repeats.
-  void StartKey();
-  // Finish tracking and report a keyup. Call only once even if key repeats.
-  void RecordEndKey(int timeline_width, int key_code);
-
-  // Track an incremental input event caused by the current pointer gesture or
-  // pressed key. Each sequence of calls to this should usually be sandwiched by
-  // startGesture/Key and recordEndGesture/Key.
-  void OnInput(double from_seconds, double to_seconds);
-
-  // Reports width to UMA the first time the media starts playing.
-  void RecordPlaying(WebScreenOrientationType,
-                     bool is_fullscreen,
-                     int timeline_width);
-
- private:
-  enum class State {
-    // No active gesture. Progresses to kKeyDown on |startKey|, or
-    // kGestureFromThumb/kGestureFromElsewhere on |startGesture|.
-    kInactive,
-
-    // Pointer down on thumb. Progresses to kDragFromThumb in |onInput|.
-    kGestureFromThumb,
-    // Thumb is being dragged (drag started from thumb).
-    kDragFromThumb,
-
-    // Pointer down on track. Progresses to kClick in |onInput|.
-    kGestureFromElsewhere,
-    // Pointer down followed by input. Assumed to be a click, unless additional
-    // |onInput| are received - if so progresses to kDragFromElsewhere.
-    kClick,
-    // Thumb is being dragged (drag started from track).
-    kDragFromElsewhere,
-
-    // A key is currently pressed down.
-    kKeyDown
-  };
-
-  bool has_never_been_playing_ = true;
-
-  State state_ = State::kInactive;
-
-  // The following are only valid during a pointer gesture.
-  TimeTicks drag_start_time_ticks_;
-  float drag_delta_media_seconds_ = 0;
-  float drag_sum_abs_delta_media_seconds_ = 0;
-};
-
-}  // namespace blink
-
-#endif  // MediaControlTimelineMetrics_h