Support vtable_verify (new compiler option).

base/allocator/allocator.gyp

Index: base/allocator/allocator.gyp
diff --git a/base/allocator/allocator.gyp b/base/allocator/allocator.gyp
index e2c8ac0faeb383fd96b138b1f99b23c830ab21bb..ab597c41d39d99e0100d7afc48efcdd6dd9c0a22 100644
--- a/base/allocator/allocator.gyp
+++ b/base/allocator/allocator.gyp
@@ -6,6 +6,7 @@
   'variables': {
     'jemalloc_dir': '../../third_party/jemalloc/chromium',
     'tcmalloc_dir': '../../third_party/tcmalloc/chromium',
+    'use_vtable_verify%': 0,
   },
   'targets': [
     {
@@ -394,6 +395,16 @@
               '-Wl,-u_ZN15HeapLeakChecker12IgnoreObjectEPKv,-u_ZN15HeapLeakChecker14UnIgnoreObjectEPKv',
           ]},
         }],
+        [ 'use_vtable_verify==1', {
+          'cflags': [
+            '-Wno-sign-compare',
+            '-Wno-unused-result',
+            '-fvtable-verify=preinit',
+          ],
+          'cflags!': [
+            '-fvtable-verify=std',

[Mark Mentovai, 2012/08/15 20:21:38]

OK, so let’s talk more about this. Where’s your “gcc wrapper script” sit in the
pipeline?

[Mark Mentovai, 2012/08/15 20:38:36]

So then this line, which is supposed to exclude -fvtable-verify=std from cflags,
is entirely inoperative. Your wrapper script is passing -fvtable-verify=std to
the actual compiler driver. -fvtable-verify=std is never present in the
configuration in GYP or in the build environment (make, ninja, or whatever
else).

+          ],
+        }],
         [ 'linux_use_debugallocation==1', {
           'sources!': [
             # debugallocation.cc #includes tcmalloc.cc,