Enable Clang warnings for implementation files on all platforms.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index c61a70ea9b986932d50a2c26696f2e0ccfc7887a..e77aa3191393f55146789c4c7799f5e31dd259c7 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -1551,27 +1551,8 @@
         'grit_defines': ['-D', 'use_concatenated_impulse_responses'],
       }],
       ['clang_use_chrome_plugins==1 and OS!="win"', {
-        'variables': {
-          'clang_chrome_plugins_flags': [
-            '<!@(<(DEPTH)/tools/clang/scripts/plugin_flags.sh)'
-          ],
-        },
-        'conditions': [
-          ['OS=="linux" or OS=="mac"', {
-            'clang_chrome_plugins_flags': [
-              '<@(clang_chrome_plugins_flags)'
-            ],
-          }, {
-            # TODO(rsleevi): http://crbug.com/115047 - This warning is only
-            # enabled for Linux for now. Disable everywhere else.
-            'clang_chrome_plugins_flags': [
-              '<@(clang_chrome_plugins_flags)',
-              '-Xclang',
-              '-plugin-arg-find-bad-constructs',
-              '-Xclang',
-              'skip-virtuals-in-implementations',
-            ],
-          }]
+        'clang_chrome_plugins_flags': [
+          '<!@(<(DEPTH)/tools/clang/scripts/plugin_flags.sh)'
         ],
       }],