Enable warning on ASan-enabled build

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 93016e2db7d0aff8f5e361f3fcac5223486d14c2..5c1ebb834cf727e176f36b65a964ac24f61a2e20 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -3974,7 +3974,7 @@
               ['_toolset=="target"', {
                 'cflags': [
                   '-fsanitize=address',
-                  '-w',  # http://crbug.com/162783
+                  '-Wno-error=macro-redefined',  # http://crbug.com/162783
                 ],
                 'ldflags': [
                   '-fsanitize=address',
@@ -3985,6 +3985,7 @@
               ['OS=="mac"', {
                 'cflags': [
                   '-mllvm -asan-globals=0',  # http://crbug.com/352073
+                  '-Wno-error=unused-function',  # http://crbug.com/162783
                 ],
               }],
             ],
@@ -3996,7 +3997,7 @@
                   '-fsanitize=undefined',
                   # -fsanitize=vptr is incompatible with -fno-rtti.
                   '-fno-sanitize=vptr',
-                  '-w',  # http://crbug.com/162783
+                  '-Wno-error=macro-redefined',  # http://crbug.com/162783
                 ],
                 'ldflags': [
                   '-fsanitize=undefined',
@@ -4005,6 +4006,13 @@
                 ],
               }],
             ],
+            'conditions': [
+              ['OS=="mac"', {
+                'cflags': [
+                  '-Wno-error=unused-function',  # http://crbug.com/162783
+                ],
+              }],
+            ],
           }],
           ['ubsan_vptr==1', {
             'target_conditions': [
@@ -4013,7 +4021,7 @@
                   '-fsanitize=vptr',
                   '-fsanitize=null',  # Avoid dereferences on null pointer objects.
                   '-fsanitize-blacklist=<(ubsan_vptr_blacklist)',
-                  '-w',  # http://crbug.com/162783
+                  '-Wno-error=macro-redefined',  # http://crbug.com/162783
                 ],
                 'cflags_cc!': [
                   '-fno-rtti',
@@ -4029,6 +4037,13 @@
                 ],
               }],
             ],
+            'conditions': [
+              ['OS=="mac"', {
+                'cflags': [
+                  '-Wno-error=unused-function',  # http://crbug.com/162783
+                ],
+              }],
+            ],
           }],
           ['asan_coverage!=0', {
             'target_conditions': [
@@ -4602,7 +4617,8 @@
               # binaries on x86_64 host is problematic.
               # TODO(eugenis): re-enable.
               '-fsanitize=address',
-              '-w',  # http://crbug.com/162783
+              '-Wno-error=macro-redefined',  # http://crbug.com/162783
+
             ],
             'ldflags!': [
               '-fsanitize=address',
@@ -4613,6 +4629,13 @@
               '-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"', {
@@ -4765,7 +4788,8 @@
               'OTHER_CFLAGS': [
                 '-fsanitize=address',
                 '-mllvm -asan-globals=0',  # http://crbug.com/352073
-                '-w',  # http://crbug.com/162783
+                '-Wno-error=macro-redefined',  # http://crbug.com/162783
+                '-Wno-error=unused-function',  # http://crbug.com/162783
                 '-gline-tables-only',
               ],
             },