Add base_unittests to win8 trybot. Fix PEImage tests.

base/base.gyp

Index: base/base.gyp
diff --git a/base/base.gyp b/base/base.gyp
index 5eff44734e7ee9983765685228eeb3d98756488f..ac999393bb34d05acf3258149fa542236f01fbb6 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -769,6 +769,9 @@
             'message_loop/message_pump_libevent_unittest.cc',
             'threading/worker_pool_posix_unittest.cc',
           ],
+          'dependencies': [
+            'pe_image_test',
+          ],
           # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
           'msvs_disabled_warnings': [
             4267,
@@ -1538,6 +1541,26 @@
             },
           },
         },
+        {
+          'target_name': 'pe_image_test',
+          'type': 'shared_library',
+          'sources': [
+            'win/pe_image_test.cc',
+          ],
+          'msvs_settings': {
+            'VCLinkerTool': {
+              'SubSystem': '2',         # Set /SUBSYSTEM:WINDOWS
+              'DelayLoadDLLs': [
+                'cfgmgr32.dll',
+                'shell32.dll',
+              ],
+              'AdditionalDependencies': [
+                'cfgmgr32.lib',
+                'shell32.lib',
+              ],
+            },
+          },
+        },
       ],
     }],
     ['test_isolation_mode != "noop"', {