Remove comparison operator for WebMouseWheel and WebTouchEvent.

Add helper to MainThreadEventQueue unittest to compare the fields
of the classes instead of using a memcmp function.

BUG=836826

Change-Id: Iaa280074743593d8687ce923c48f778d16f1d4fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1979260
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: David Bokan <bokan@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728035}

third_party/blink/public/common/input/web_mouse_wheel_event.h

@@ -124,11 +124,6 @@ class BLINK_COMMON_EXPORT WebMouseWheelEvent : public WebMouseEvent {
   bool IsCancelable() const { return dispatch_type == kBlocking; }
 };
 
-inline bool operator==(const WebMouseWheelEvent& a,
-                       const WebMouseWheelEvent& b) {
-  return memcmp(&a, &b, a.size()) == 0;
-}
-
 }  // namespace blink
 
 #endif  // THIRD_PARTY_BLINK_PUBLIC_COMMON_INPUT_WEB_MOUSE_WHEEL_EVENT_H_