Revert 110710 - Add ChromeBrowserMainExtraParts for non main parts.

Revert 110710 - Add ChromeBrowserMainExtraParts for non main parts.

Revert 110741 - Fix ProcessSingletonTest.StartupRaceCondition for win.

    This was originally submitted as http://codereview.chromium.org/8539038/ which was reverted because of a failing test on win.
    
    This reverts the code back to a single instance of BrowserMainParts, with auxillary parts (Gtk, Views, Aura, Touch) implemented from a new base class, ChromeBrowserParts, which has a Chrome specific interface, allowing initialization to be better subdivided.
    
    This should fix the notifications auto tests.
    
    This CL also addresses the test failure on win (and a test failure on linux_chromeos triggered by the windows fix).
    
BUG=103821
TEST=Make sure all tests and autotests run
    
TBR=stevenjb@chromium.org

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=110753

[stevenjb, 2011-11-18 21:32:05]

Sigh.
http://build.chromium.org/p/chromium/builders/XP%20Tests%20%282%29/builds/9791

[Scott Hess - ex-Googler, 2011-11-18 21:33:19]

lgtm.  fingers crossed.