Avoid unnecessary gloweffect calls

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 958419eb306af5bcd1bc1b8a0b022095b9941ee5..52812352469e3fc9a54bd7168d2cd03611ab285b 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -2272,8 +2272,14 @@ bool LayerTreeHostImpl::ScrollBy(const gfx::Point& viewport_point,
         break;
     }
 
-    if (layer_impl == InnerViewportScrollLayer())
+    if (layer_impl == InnerViewportScrollLayer()) {
       unused_root_delta.Subtract(applied_delta);
+      const float kOverscrollEpsilon = 0.01f;
+      if (std::abs(unused_root_delta.x()) < kOverscrollEpsilon)
+        unused_root_delta.set_x(0.0f);
+      if (std::abs(unused_root_delta.y()) < kOverscrollEpsilon)
+        unused_root_delta.set_y(0.0f);
+    }
 
     did_lock_scrolling_layer_ = true;
     if (!should_bubble_scrolls_) {