Revert of mac: Fix tab dragging visual bug in Yosemite.

Revert of mac: Fix tab dragging visual bug in Yosemite. (https://codereview.chromium.org/379293003/)

Reason for revert:
This possibly broke interactive_ui_tests on mac:
http://build.chromium.org/p/chromium.mac/buildstatus?builder=Mac10.6%20Tests%20%281%29&number=53880

Original issue's description:
> mac: Fix tab dragging visual bug in Yosemite.
> 
> In OSX 10.10+, all views must be added to the NSWindow's contentView. Some
> views (like the tab strip and the profile icon) are placed on top of the title
> bar and require special treatment. All other views are added as subviews of
> 'chromeContentView' in TabWindowController.  This allows tab dragging and
> fullscreen logic to easily move the views that don't need special treatment.
> 
> This CL also removes the instances where a VersionIndependentWindow's
> contentView gets replaced by setContentView:. Instead, the 'chromeContentView'
> gets passed around as a subview. This allows VersionIndependentWindow to remove
> another of its internal hacks.
> 
> BUG=392239
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=283166

TBR=andresantoso@chromium.org,shess@chromium.org,erikchen@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=392239
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=283168

[Michael Achenbach, 2014-07-15 09:25:26]

Created Revert of mac: Fix tab dragging visual bug in Yosemite.

[commit-bot: I haz the power, 2014-07-15 09:26:48]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/machenbach@chromium.org/390313002/1

[commit-bot: I haz the power, 2014-07-15 09:29:07]

Change committed as 283168