Revert "RemoteMacViews: Fix hang at command-Q"

This reverts commit 464fae69315d22b6bce86525bb73305bd0cc7296.

Reason for revert: Causes heavy flakiness (14/17 on Mac 10.11) and attempted fix showed no effect: https://crrev.com/c/1369136

TBR=ccameron@chromium.org
Bug: 902583

Original change's description:
> RemoteMacViews: Fix hang at command-Q
> 
> When we call -[NSApp terminate] in the app shim process, this does
> not immediately terminate. Rather, it
>  0. Sends the message appShimController_->host()->QuitApp() and waits
>     for a reply before actually terminating.
>  1. In the browser, this call hits ExtensionAppShimHandler::
>     CloseBrowsersForApp
>  2. Which will end up calling NativeWidgetMac::Close
>  3. Which will then politely request that the app shim process close
>     the corresponding window via
>     views_bridge_mac::mojom::BridgedNativeWidget::CloseWindow
>  4. Which will send an ack back to the browser via
>     views_bridge_mac::mojom::BridgedNativeWidgetHost::OnWindowHasClosed
>  5. Whereupon the browser window will be registered as closed, and a
>     close message will be sent to the app shim, and the wait for
>     termination will break
> 
> This ends up not working at step 3. Our suspended terminate ends up
> running a nested message loop inside a mojo message handler, and so
> it will never execute the CloseWindow message, and therefore never
> close.
> 
> Change the logic at [0] to send the QuitApp message, and then
> immediately terminate the application.
> 
> Bug: 902583
> Change-Id: I60fd7b5fdf9f145369d06219e8ebef36cdcd0f44
> Reviewed-on: https://chromium-review.googlesource.com/c/1364220
> Reviewed-by: Robert Sesek <rsesek@chromium.org>
> Commit-Queue: ccameron <ccameron@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#614922}

TBR=ccameron@chromium.org,rsesek@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 902583
Change-Id: I34a3300dc188cdd0de58692042ce131a8639117f
Reviewed-on: https://chromium-review.googlesource.com/c/1371475
Reviewed-by: Friedrich Horschig [CET] <fhorschig@chromium.org>
Commit-Queue: Friedrich Horschig [CET] <fhorschig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615485}
4 files changed