Drop unneeded warning suppression on mac

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index fb53e9264fb6062ca559700f1a3ab9a21ea5aca0..e03f563da92a23347d0c62ffe1f7f95937de8bf3 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -3996,7 +3996,6 @@
               ['OS=="mac"', {
                 'cflags': [
                   '-mllvm -asan-globals=0',  # http://crbug.com/352073
-                  '-Wno-error=unused-function',  # http://crbug.com/162783
                 ],
               }],
             ],
@@ -4016,13 +4015,6 @@
                 ],
               }],
             ],
-            'conditions': [
-              ['OS=="mac"', {
-                'cflags': [
-                  '-Wno-error=unused-function',  # http://crbug.com/162783
-                ],
-              }],
-            ],
           }],
           ['ubsan_vptr==1', {
             'target_conditions': [
@@ -4046,13 +4038,6 @@
                 ],
               }],
             ],
-            'conditions': [
-              ['OS=="mac"', {
-                'cflags': [
-                  '-Wno-error=unused-function',  # http://crbug.com/162783
-                ],
-              }],
-            ],
           }],
           ['asan_coverage!=0', {
             'target_conditions': [
@@ -4636,13 +4621,6 @@
               '-Wl,--warn-shared-textrel',
               '-Wl,--fatal-warnings',
             ],
-            'conditions': [
-              ['OS=="mac"', {
-                'cflags!': [
-                  '-Wno-error=unused-function',  # http://crbug.com/162783
-                ],
-              }],
-            ],
           }],
           # Settings for building host targets on mac.
           ['_toolset=="host" and host_os=="mac"', {
@@ -4795,7 +4773,6 @@
               'OTHER_CFLAGS': [
                 '-fsanitize=address',
                 '-mllvm -asan-globals=0',  # http://crbug.com/352073
-                '-Wno-error=unused-function',  # http://crbug.com/162783
                 '-gline-tables-only',
               ],
             },