Stop triggering context menu while scrolling

ios/web/web_state/ui/crw_context_menu_controller.mm

Index: ios/web/web_state/ui/crw_context_menu_controller.mm
diff --git a/ios/web/web_state/ui/crw_context_menu_controller.mm b/ios/web/web_state/ui/crw_context_menu_controller.mm
index 335094014f101794112c7aaadf92ef4b442bfb73..74d59fd1ee7b4d31ccf6cac1e229dfc59354b805 100644
--- a/ios/web/web_state/ui/crw_context_menu_controller.mm
+++ b/ios/web/web_state/ui/crw_context_menu_controller.mm
@@ -303,6 +303,14 @@ - (BOOL)gestureRecognizer:(UIGestureRecognizer*)gestureRecognizer
 - (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer*)gestureRecognizer {
   // Expect only _contextMenuRecognizer.
   DCHECK([gestureRecognizer isEqual:_contextMenuRecognizer]);
+
+  // Context menu should not be triggered while scrolling, as some users tend to
+  // stop scrolling by resting the finger on the screen instead of touching the
+  // screen. For more info, please refer to crbug.com/642375.
+  if ([self webScrollView].isDragging) {

[Eugene But (OOO till 7-30), 2017/01/18 00:20:00]

self.webScrollView.dragging

From Style Guide: "Dot notation is used only with property names, not with
method names."
go/objc-style?showone=Objective-C_Method_Names&cl=head#Objective-C_Method_Names

[liaoyuke, 2017/01/18 00:26:47]

Done.

+    return false;

[Eugene But (OOO till 7-30), 2017/01/18 00:20:00]

s/false/NO

[liaoyuke, 2017/01/18 00:26:47]

Done.

+  }
+
   // Fetching is considered as successful even if |_DOMElementForLastTouch| is
   // empty. However if |_DOMElementForLastTouch| is empty then custom context
   // menu should not be shown.