(Merge to M45): Revert of BrowserWindowCocoa::Show should activate the window (patchset #1 id:1 of …

(Merge to M45): Revert of BrowserWindowCocoa::Show should activate the window (patchset #1 id:1 of https://codereview.chromium.org/1166643003/ )

Reason for revert:
Caused regression: http://crbug.com/500038, and http://crbug.com/496786

Original issue's description:
> BrowserWindowCocoa::Show should activate the window
>
> When a new tab/window is opened on Mac, the window is currently brought
> to the front relative to other Chrome windows, but not relative to other
> apps. This often goes unnoticed, since Chrome is often already the
> active app, but it's particularly noticeable when clicking on a push
> notification opens a new tab/window, as this window will remain
> underneath other apps if Chrome wasn't already in the foreground.
>
> This patch makes Show always Activate the window as well.
>
> BUG=470830
> TEST=manual, follow steps in https://crbug.com/470830
>
> Committed: https://crrev.com/b13b6d7b2c7ad67c1b1937897fe3c26527eeb943
> Cr-Commit-Position: refs/heads/master@{#332615}

TBR=avi@chromium.org,johnme@chromium.org
NOTREECHECKS=true
BUG=470830, 500038
Review URL: https://codereview.chromium.org/1359483002

Cr-Commit-Position: refs/heads/master@{#349884}
(cherry picked from commit bfacce0691d0ffe7551e2b35a816c1503a9d489a)

Committed: https://chromium.googlesource.com/chromium/src/+/ddea003bedb8714337e45594d38793033bf72162

[Andre, 2015-09-22 22:44:45]

Committed patchset #1 (id:1) manually as
ddea003bedb8714337e45594d38793033bf72162 (tree was closed).