Use scroll-boundary-behavior to control overscroll-refresh/glow on android.

ui/android/overscroll_refresh.h

Index: ui/android/overscroll_refresh.h
diff --git a/ui/android/overscroll_refresh.h b/ui/android/overscroll_refresh.h
index 7cb98e272ce711c843103d3b2ffa62d33b9296b5..9fd7b49705564319bdf12886bb9b7570c76fbe81 100644
--- a/ui/android/overscroll_refresh.h
+++ b/ui/android/overscroll_refresh.h
@@ -37,9 +37,11 @@ class UI_ANDROID_EXPORT OverscrollRefresh {
   // Returns whether the refresh was activated.
   void OnScrollEnd(const gfx::Vector2dF& velocity);
 
-  // Scroll ack listener. The effect will only be activated if the initial
-  // updates go unconsumed.
-  void OnScrollUpdateAck(bool was_consumed);
+  // Scroll ack listener. The effect will only be activated if the controller
+  // decides it can navigate if the scroll_update is not consumed and the
+  // scroll_boundary_behavior on y axis is 'auto'. See how it's called in

[majidvp, 2017/08/08 15:16:14]

nit: This sentence does not read well. It has two back to back 'if'.

Suggestion:
The effect will only be activated if |can_navigate| is true which happens when
the scroll update is not consumed and the scroll_boundary_behavior on y axis is
'auto'.

[sunyunjia, 2017/08/10 16:17:27]

Done.

+  // OverscrollControllerAndroid.

[majidvp, 2017/08/08 15:16:14]

nit: This last sentence seems unnecessary.

[sunyunjia, 2017/08/10 16:17:27]

Done.

+  virtual void OnOverscrolled(bool can_navigate);
 
   // Returns true if the effect has consumed the |scroll_delta|.
   bool WillHandleScrollUpdate(const gfx::Vector2dF& scroll_delta);
@@ -58,10 +60,10 @@ class UI_ANDROID_EXPORT OverscrollRefresh {
   void Reset();
 
   // Returns true if the refresh effect is either being manipulated or animated.
-  bool IsActive() const;
+  virtual bool IsActive() const;
 
   // Returns true if the effect is waiting for an unconsumed scroll to start.
-  bool IsAwaitingScrollUpdateAck() const;
+  virtual bool IsAwaitingScrollUpdateAck() const;
 
  private:
   void Release(bool allow_refresh);