Add missing dependencies.

chrome/chrome_tests_unit.gypi

 # Copyright 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 {
   'variables': {
     'chrome_unit_tests_sources': [
       # histograms.xml is analyzed by AboutFlagsHistogramTest, so this
       # dependency is needed to make commit bots run unit_tests on
       # histograms.xml changes.
       '../tools/metrics/histograms/histograms.xml',
@@ skipping 2864 matching lines @@
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
     ['test_isolation_mode != "noop"', {
       'targets': [
         {
           'target_name': 'unit_tests_run',
           'type': 'none',
           'dependencies': [
+            '../third_party/mesa/mesa.gyp:osmesa',

[jam, 2015/07/20 22:52:14]

here and in other places, shouldn't this be in unit_tests? that way if someone
has an empty build directory and builds just unit_tests, it should have the
binaries needed.

someone more familiar shoudl review, i couldn't figure out through cs in a quick
search how this is needed for unit tests. i.e. i see for browser tests the code
in
https://code.google.com/p/chromium/codesearch#chromium/src/content/public/tes...
which does this. i ask to know if there's one test target (like test support)
that we can add this to instead of in all these unit tests.

[M-A Ruel, 2015/07/20 23:18:46]

That's a fair question. The main difference is that the tests do not link with
it but I did it anyway since it makes more sense.

[danakj, 2015/07/20 23:56:43]

osmesa is dynamically loaded by GLSurface.

any unit test that uses a full compositor (ie most of our test suites) will use
it via
https://code.google.com/p/chromium/codesearch#chromium/src/ui/gl/gl_surface.c...

browser tests are special cuz they use gpu process not just in process gl.

it'd be nice if they are a dep of the test suite itself, but osmesa is not
linked in, so, does gyp have a way of expressing that?

             'unit_tests',
           ],
           'includes': [
             '../build/isolate.gypi',
           ],
           'sources': [
             'unit_tests.isolate',
           ],
           'conditions': [
             ['use_x11 == 1', {
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }