A 'held' event can trigger a menu (and a nested message loop), e.g. when right-clicking while a menu is already showing. In such scenario, the subsequent events that come in while the latest menu is up are not transformed correctly, because the WindowEventDispatcher notices that a held event is in the process of being dispatched. As a result, the events have incorrect coordinates (especially when device scale factor is not 1, or when the display is rotated). To fix this, instead of simply tracking whether a 'held' event is being dispatched or not, we track the 'held' event itself, and transform all the non-held events. BUG=425407 R=sky@chromium.org Review URL: https://codereview.chromium.org/829353005 Cr-Commit-Position: refs/heads/master@{#311651}