Move image_unittest_util* into gfx_test_support target.

That way we can stop building it within unit_tests and gfx_unittests and
share with them through gfx_test_support target.

This way is much more standard in chromium code.

BUG=354137
TEST=unit_tests, gfx_unittests
R=sky@chromium.org

Review URL: https://codereview.chromium.org/590873002

Cr-Commit-Position: refs/heads/master@{#296004}

chrome/chrome_tests_unit.gypi

@@ -1487,6 +1487,7 @@
         '../testing/gmock.gyp:gmock',
         '../testing/gtest.gyp:gtest',
         '../third_party/zlib/zlib.gyp:zlib',
+        '../ui/gfx/gfx.gyp:gfx_test_support',
         '../ui/message_center/message_center.gyp:message_center_test_support',
       ],
       'export_dependent_settings': [
@@ -1656,8 +1657,6 @@
         'test/logging/win/mof_data_parser.h',
         'test/logging/win/test_log_collector.cc',
         'test/logging/win/test_log_collector.h',
-        '../ui/gfx/image/image_unittest_util.cc',
-        '../ui/gfx/image/image_unittest_util.h',
       ],
       'conditions': [
         ['OS!="ios"', {

ui/gfx/gfx.gyp

@@ -426,6 +426,10 @@
       'target_name': 'gfx_test_support',
       'type': 'static_library',
       'sources': [
+        'image/image_unittest_util.cc',
+        'image/image_unittest_util.h',
+        'image/image_unittest_util_ios.mm',
+        'image/image_unittest_util_mac.mm',
         'test/fontconfig_util_linux.cc',
         'test/fontconfig_util_linux.h',
         'test/gfx_util.cc',

ui/gfx/gfx_tests.gyp

@@ -18,10 +18,6 @@
         'image/image_ios_unittest.mm',
         'image/image_skia_unittest.cc',
         'image/image_unittest.cc',
-        'image/image_unittest_util.cc',
-        'image/image_unittest_util.h',
-        'image/image_unittest_util_ios.mm',
-        'image/image_unittest_util_mac.mm',
         'screen_unittest.cc',
         'test/run_all_unittests.cc',
         'text_elider_unittest.cc',