Add missing dependencies.

cc/cc_tests.gyp

 # Copyright (c) 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': {
     'chromium_code': 1,
     'cc_unit_tests_source_files': [
       'animation/animation_host_unittest.cc',
       'animation/animation_player_unittest.cc',
@@ skipping 391 matching lines @@
         '../gpu/command_buffer/command_buffer.gyp:gles2_utils',
         '../gpu/gpu.gyp:gles2_c_lib',
         '../gpu/gpu.gyp:gles2_implementation',
         '../gpu/gpu.gyp:gl_in_process_context',
         '../gpu/gpu.gyp:gpu',
         '../gpu/gpu.gyp:gpu_unittest_utils',
         '../gpu/skia_bindings/skia_bindings.gyp:gpu_skia_bindings',
         '../skia/skia.gyp:skia',
         '../testing/gmock.gyp:gmock',
         '../testing/gtest.gyp:gtest',
-        '../third_party/mesa/mesa.gyp:osmesa',
         '../ui/gfx/gfx.gyp:gfx',
         '../ui/gfx/gfx.gyp:gfx_geometry',
         '../ui/gfx/gfx.gyp:gfx_test_support',
         '../ui/gl/gl.gyp:gl',
         '../ui/gl/gl.gyp:gl_test_support',
+        # Only needed at runtime.
+        '../third_party/mesa/mesa.gyp:osmesa',
       ],
       'sources': [
         '<@(cc_tests_support_files)',
       ],
     },
   ],
   'conditions': [
     ['OS == "android"',
       {
         'targets': [
@@ skipping 45 matching lines @@
                   '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
                 ],
               }
             ],
           ],
         },
       ],
     }],
   ],
 }