ChromeOS: Do not use TraceStackFramePointers() with MSAN.

chrome/browser/chromeos/libc_close_tracking.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <errno.h>
 #include <sys/syscall.h>
 #include <unistd.h>
 
 #include <sstream>
 #include <string>
@@ skipping 101 matching lines @@
   const int ret = IGNORE_EINTR(syscall(SYS_close, fd));
   // Captures errno and restores it later in case it is changed.
   const ErrnoCapture close_errno;
 
   // Return if tracking is not enabled for the current process.
   if (!g_stack_tracker || !g_stack_tracker->ShouldTrack())
     return ret;
 
   // Capture stack for successful close.
   if (ret == 0) {
-#if HAVE_TRACE_STACK_FRAME_POINTERS
+#if HAVE_TRACE_STACK_FRAME_POINTERS && !defined(MEMORY_SANITIZER)
     // Use TraceStackFramePointers because the backtrack() based default
     // capturing gets only the last stack frame and is not useful.
+    // With the exception of when MSAN is enabled. See comments for why
+    // StackTraceTest.TraceStackFramePointers is disabled in MSAN builds.
     const void* frames[64];
     const size_t frame_count =
         base::debug::TraceStackFramePointers(frames, arraysize(frames), 0);
     g_stack_tracker->SetStack(fd, base::debug::StackTrace(frames, frame_count));
 #else
     // Use default StackTrace when TraceStackFramePointers is not available.
     // Hopefully it will capture something useful.
     g_stack_tracker->SetStack(fd, base::debug::StackTrace());
 #endif
     return ret;
@@ skipping 41 matching lines @@
 const base::debug::StackTrace* GetLastCloseStackForTest(int fd) {
   return g_stack_tracker ? g_stack_tracker->GetStack(fd) : nullptr;
 }
 
 void SetCloseTrackingIgnorePidForTest(bool ignore_pid) {
   DCHECK(g_stack_tracker);
   g_stack_tracker->set_ignore_pid(ignore_pid);
 }
 
 }  // namespace chromeos