Add support for writing unit tests for Mojo-backed apps/extensions APIs.

chrome/chrome_tests_unit.gypi

Index: chrome/chrome_tests_unit.gypi
diff --git a/chrome/chrome_tests_unit.gypi b/chrome/chrome_tests_unit.gypi
index f5c2b33ce1b0e1d3213486c8bf38528ab8404a8b..b4d4f040e7dacd77c979f6318fc061ad270b15dd 100644
--- a/chrome/chrome_tests_unit.gypi
+++ b/chrome/chrome_tests_unit.gypi
@@ -600,6 +600,9 @@
         '../extensions/common/url_pattern_unittest.cc',
         '../extensions/common/user_script_unittest.cc',
         '../extensions/renderer/activity_log_converter_strategy_unittest.cc',
+        '../extensions/renderer/api_test_base.cc',
+        '../extensions/renderer/api_test_base.h',
+        '../extensions/renderer/api_test_base_unittest.cc',
         '../extensions/renderer/event_unittest.cc',
         '../extensions/renderer/json_schema_unittest.cc',
         '../extensions/renderer/messaging_utils_unittest.cc',
@@ -2035,6 +2038,9 @@
             '../extensions/extensions_resources.gyp:extensions_resources',
             '../extensions/extensions_strings.gyp:extensions_strings',
             '../gpu/gpu.gyp:gpu_unittest_utils',
+            '../mojo/mojo.gyp:mojo_cpp_bindings',
+            '../mojo/mojo.gyp:mojo_js_bindings',
+            '../mojo/mojo.gyp:mojo_js_bindings_lib',
             '../media/media.gyp:media_test_support',
             '../ppapi/ppapi_internal.gyp:ppapi_unittest_shared',
             '../third_party/leveldatabase/leveldatabase.gyp:leveldatabase',
@@ -2053,6 +2059,7 @@
           ],
           'include_dirs': [
             '<(SHARED_INTERMEDIATE_DIR)/chrome',
+            '<(SHARED_INTERMEDIATE_DIR)/content',
           ],
         }, {  # OS=="ios"
           'dependencies': [