Revert of Tab/Desktop Capture: Use requests instead of timer-based refreshing.

media/capture/content/video_capture_oracle.h

Index: media/capture/content/video_capture_oracle.h
diff --git a/media/capture/content/video_capture_oracle.h b/media/capture/content/video_capture_oracle.h
index 92a63a45a9c8b58c477691bec299a27c97b4d3e8..8c4f6827e582d8ed7fe5f64ce8418143ff392b78 100644
--- a/media/capture/content/video_capture_oracle.h
+++ b/media/capture/content/video_capture_oracle.h
@@ -24,11 +24,17 @@
 class MEDIA_EXPORT VideoCaptureOracle {
  public:
   enum Event {
+    kTimerPoll,
     kCompositorUpdate,
-    kActiveRefreshRequest,
-    kPassiveRefreshRequest,
     kMouseCursorUpdate,
     kNumEvents,
+  };
+
+  enum {
+    // The recommended minimum amount of time between calls to
+    // ObserveEventAndDecideCapture() for the kTimerPoll Event type.  Anything
+    // lower than this isn't harmful, just wasteful.
+    kMinTimerPollPeriodMillis = 125,  // 8 FPS
   };
 
   VideoCaptureOracle(base::TimeDelta min_capture_period,
@@ -98,10 +104,6 @@
     return last_time_animation_was_detected_;
   }
 
-  // Returns a NUL-terminated string containing a short, human-readable form of
-  // |event|.
-  static const char* EventAsString(Event event);
-
  private:
   // Retrieve/Assign a frame timestamp by capture |frame_number|.  Only valid
   // when IsFrameInRecentHistory(frame_number) returns true.