https://codereview.chromium.org/1783313003 broke compile on WebKit Linux MSAN when the corresponding v8 roll went it:

https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20MSAN/builds/8979

I reverted the v8 roll in https://codereview.chromium.org/1788763004/, and I'm filing this to make sure someone follows up on this.  I've stopped the v8 rolls in the meantime.

Output from failed bot:
... ../../v8/src/heap/heap.cc -o obj/v8/src/heap/v8_base.heap.o
../../v8/src/heap/heap.cc:1588:54: error: use of undeclared identifier 'size'; did you mean 'ConstantPoolEntry::size'?
    MSAN_MEMORY_IS_INITIALIZED(&entry->size_, sizeof(size));
                                                     ^~~~
                                                     ConstantPoolEntry::size
../../v8/src/msan.h:27:64: note: expanded from macro 'MSAN_MEMORY_IS_INITIALIZED'
#define MSAN_MEMORY_IS_INITIALIZED(p, s) __msan_unpoison((p), (s))
                                                               ^
../../v8/src/assembler.h:1222:14: note: 'ConstantPoolEntry::size' declared here
  static int size(Type type) {
             ^
../../v8/src/heap/heap.cc:1588:53: error: invalid application of 'sizeof' to a function type
    MSAN_MEMORY_IS_INITIALIZED(&entry->size_, sizeof(size));
                                                    ^~~~~~
../../v8/src/msan.h:27:64: note: expanded from macro 'MSAN_MEMORY_IS_INITIALIZED'
#define MSAN_MEMORY_IS_INITIALIZED(p, s) __msan_unpoison((p), (s))
                                                               ^
../../v8/src/heap/heap.cc:1589:53: error: use of undeclared identifier 'obj'
    MSAN_MEMORY_IS_INITIALIZED(&entry->obj_, sizeof(obj));

CC-ing v8 sheriffs and people from the culprit CL.