GN: Only define UNIT_TEST in direct gtest deps

GN: Only define UNIT_TEST in direct gtest deps

This matches the gyp build and is important for parts of the code that
guard their API with UNIT_TEST. For instance,
chrome/browser/ui/views/omnibox/omnibox_view_views.h has a GetRenderText
function guarded by #if UNIT_TEST that shadows a protected function
GetRenderText from its parent class views::Textfield, but with different
const-ness. If c/b/u/v/o/omnibox_view_views.cc is compiled with UNIT_TEST
set, it attempts to use the guarded member function instead of the base
class which fails to compile.

R=brettw@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=288988

[jamesr, 2014-08-12 05:53:29]

In gyp the UNIT_TEST define is set for direct dependents hee:

https://code.google.com/p/chromium/codesearch#chromium/src/testing/gtest.gyp&...

[brettw, 2014-08-12 05:55:08]

lgtm

[jamesr, 2014-08-12 05:56:07]

The CQ bit was checked by jamesr@chromium.org

[commit-bot: I haz the power, 2014-08-12 05:56:45]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jamesr@chromium.org/464503003/1

[commit-bot: I haz the power, 2014-08-12 07:48:54]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_dbg_triggered_tests on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_dbg_tri...)

[commit-bot: I haz the power, 2014-08-12 15:45:25]

Change committed as 288988