Linux: Enable ODR violation detection. (try 2)

BUG=449754

Review URL: https://codereview.chromium.org/988633004

Cr-Original-Commit-Position: refs/heads/master@{#319577}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 82d64ef43c1d15e1cc25d4b0d38dc314a0f565c0

common.gypi

@@ -4490,6 +4490,14 @@
                   # '-Wl,--threads',
                   # '-Wl,--thread-count=4',
                 ],
+                'conditions': [
+                  # TODO(thestig): Enable this for disabled cases.
+                  [ 'buildtype!="Official" and chromeos==0 and asan==0 and lsan==0 and tsan==0 and msan==0 and ubsan==0 and ubsan_vptr==0', {
+                    'ldflags': [
+                      '-Wl,--detect-odr-violations',
+                    ],
+                  }],
+                ],
               }],
             ],
             'conditions': [

config/compiler/BUILD.gn

@@ -78,7 +78,7 @@ if (!is_win) {
 #
 # Base compiler configuration.
 #
-# See also "runtime_library" below for related stuff and a discusison about
+# See also "runtime_library" below for related stuff and a discussion about
 # where stuff should go. Put warning related stuff in the "warnings" config.
 
 config("compiler") {
@@ -399,6 +399,13 @@ config("compiler") {
       #"-Wl,--threads",
       #"-Wl,--thread-count=4",
     ]
+
+    # TODO(thestig): Make this flag work with GN.
+    #if (!is_official_build && !is_chromeos && !(is_asan || is_lsan || is_tsan || is_msan)) {
+    #  ldflags += [
+    #    "-Wl,--detect-odr-violations",
+    #  ]
+    #}
   }
 
   if (linux_use_bundled_binutils) {
@@ -719,7 +726,6 @@ config("default_warnings") {
   if (is_win) {
     cflags = [
       "/WX",  # Treat warnings as errors.
-
       # Warnings permanently disabled:
 
       # TODO(GYP) The GYP build doesn't have this globally enabled but disabled
@@ -774,7 +780,6 @@ config("default_warnings") {
       # have to turn off this warning (and be careful about how object
       # destruction happens in such cases).
       "/wd4611",
-
       # Warnings to evaluate and possibly fix/reenable later:
 
       "/wd4100",  # Unreferenced formal function parameter.