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

third_party/WebKit/Source/core/input/ScrollManager.cpp

Index: third_party/WebKit/Source/core/input/ScrollManager.cpp
diff --git a/third_party/WebKit/Source/core/input/ScrollManager.cpp b/third_party/WebKit/Source/core/input/ScrollManager.cpp
index 2ec9de28fe33891ae1d881337a6d7b6ba78c3cd7..9a9acccddcf6cc532c0db03ec5a28aab0c871442 100644
--- a/third_party/WebKit/Source/core/input/ScrollManager.cpp
+++ b/third_party/WebKit/Source/core/input/ScrollManager.cpp
@@ -87,6 +87,9 @@ AutoscrollController* ScrollManager::GetAutoscrollController() const {
 
 static bool CanPropagate(const ScrollState& scroll_state,
                          const Element& element) {
+  if (!element.GetLayoutBox()->GetScrollableArea())

[chrishtr, 2017/08/25 20:55:06]

Why did you need to change this?

[sunyunjia, 2017/08/25 21:19:44]

This is a bug in the previous patch--the scroll-chaining part of
scroll-boundary-behavior. We would like the scroll-boundary-behavior affects
only the scrollable containers, not all the elements.

Specifically, if the body has scroll-boundary-behavior: contain, and it hasn't
been added to the scroll-chain because it's not scrollable, the scroll-chain
would be cut from that point. Then the overscroll message won't be generated at
all, because it is only generated at the rootscroller level, which is the
document. And we won't have the glow-effect we would still like to see with the
value "contain"

We don't need this check at cc side, because for now, cc handles overscroll
outside the scroll-chain. Cutting scroll-chain early won't affect overscroll.
See crbug.com/755164 .

You can find the discussion at
message143(https://codereview.chromium.org/2884423003/#msg143) and
message152(https://codereview.chromium.org/2884423003/#msg152)

+    return true;
+
   return (scroll_state.deltaXHint() == 0 ||
           element.GetComputedStyle()->ScrollBoundaryBehaviorX() ==
               EScrollBoundaryBehavior::kAuto) &&