Repository: vue
Issue: Click Event Triggers on Complex Buttons are ignored in some environments
Labels: contribution welcome,browser quirks,has PR

### Version
2.6.10

### Reproduction link
[https://jsfiddle.net/s7hyqk13/2/](https://jsfiddle.net/s7hyqk13/2/)







### Steps to reproduce
1. Configure one of the Adobe CEP [Sample Panels](https://github.com/Adobe-CEP/Samples). The [PProPanel](https://github.com/Adobe-CEP/Samples/tree/master/PProPanel) is a good starting point as it has very clear documentation on how to [set up the environment](https://github.com/Adobe-CEP/Samples/tree/master/PProPanel#2-enable-loading-of-unsigned-panels) for testing.
1. Replace the HTML/JavaScript/CSS contents of the panel project with the contents of the [linked JSFiddle](https://jsfiddle.net/s7hyqk13/2/).
1. Open the panel.
1. Attach a debugger (with the default PProPanel setup this would mean browsing to `localhost:7777` in Chrome).
1. Set the "_Mouse > `click`_" **Event Listener Breakpoint** in the "Sources" tab of the Chrome Debugger.
1. Click the Vue icon in the center of the silver `div`.

### What is expected?
Method bound to the `@click` handler is triggered when the image embedded in the parent div is clicked. 

### What is actually happening?
The method bound to the `@click` handler is _only_ triggered when clicking outside of the parent div.

---
This is a non-trivial bug to reproduce as the only place I've experienced it is in [Adobe CEP](https://github.com/Adobe-CEP/CEP-Resources/blob/master/CEP_9.x/Documentation/CEP%209.0%20HTML%20Extension%20Cookbook.md) extensions (which run NW.js under the hood). That said, it does reproduce 100% of the time there.

The debugger (CEP context) seems to show several funny things at around [this line](https://github.com/vuejs/vue/blob/d40b7ddb8177944d1dd50f4f780e6fd92c9455c2/src/platforms/web/runtime/modules/events.js#L69) in the Vue events.js file. Specifically:

1. The `e.timeStamp` value **does not change** between callbacks for _different buttons/elements_.
1. The `attachedTimestamp` is **_significantly_ larger** than the `e.timeStamp` value.
1. The `attachedTimestamp` value _does_ change when the component is updated (the `e.timeStamp` remains identical).

I should note that this affects at least [CEP 8.0 and CEP 9.0](https://github.com/Adobe-CEP/CEP-Resources/blob/master/CEP_9.x/Documentation/CEP%209.0%20HTML%20Extension%20Cookbook.md#chromium-embedded-framework-cef) (tested in Premiere Pro).

**Vue Versions Note:** This broke somewhere between versions 2.5.17 and 2.6.x. If we run a version of 2.5 (2.5.17 and some earlier versions verified), then this issue does not occur. In testing 2.6.x, we've found that this same issue occurs from 2.6.5 to 2.6.10 (latest). Versions of 2.6 prior to 2.6.5 are actually _worse_ in that the buttons basically don't work at all.

**Important Note:** I should _further_ note that apparently right-clicking to open the basic CEF [not CEP] context menu will cause the `e.timeStamp` values to begin reporting as expected. Once this occurs, the buttons will _also_ work as expected. That said, we shouldn't have to instruct users to right-click prior to interfacing with the extension.

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