Explicitly specify whether to emit frame pointers by default.

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 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.
 
 import("//build/config/android/config.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/nacl/config.gni")
 import("//build/toolchain/cc_wrapper.gni")
@@ skipping 1363 matching lines @@
     common_optimize_on_ldflags += [
       # Specifically tell the linker to perform optimizations.
       # See http://lwn.net/Articles/192624/ .
       "-Wl,-O1",
       "-Wl,--gc-sections",
     ]
   }
 }
 
 config("default_stack_frames") {
-  if (is_posix && !(is_mac || is_ios)) {
-    if (using_sanitizer || enable_profiling || is_debug ||
-        current_cpu == "arm64") {
-      # Explicitly ask for frame pointers, otherwise:
-      # * Stacks may be missing for sanitizer and profiling builds.
-      # * Debug tcmalloc can crash (crbug.com/636489).
-      # * Stacks may be missing for arm64 crash dumps (crbug.com/391706).
+  if (is_posix) {
+    if (enabled_frame_pointers) {
       cflags = [ "-fno-omit-frame-pointer" ]
-    } else if (is_android) {
+    } else {
       cflags = [ "-fomit-frame-pointer" ]
     }
   }
+  # On Windows, the flag to enable framepointers "/Oy-" must always come after
+  # the optimization flag [e.g. "/O2"]. The optimization flag is set by one of
+  # the "optimize" configs, see rest of this file. The ordering that cflags are
+  # applied is well-defined by the GN spec, and there is no way to ensure that
+  # cflags set by "default_stack_frames" is applied after those set by an
+  # "optimize" confnig. Similarly, there is no way to propagate state from this

[brettw, 2017/04/03 21:17:42]

confnig spelling

+  # config into the "optimize" config. We always apply the "/Oy-" config in the
+  # definition for common_optimize_on_cflags definition, even though this may
+  # not be correct.
 }
 
 # Default "optimization on" config.
 config("optimize") {
   if (is_win) {
     # TODO(thakis): Remove is_clang here, https://crbug.com/598772
     if (is_official_build && full_wpo_on_official && !is_clang) {
       common_optimize_on_cflags += [
         "/GL",  # Whole program optimization.
 
@@ skipping 306 matching lines @@
 
 if (is_ios || is_mac) {
   # On Mac and iOS, this enables support for ARC (automatic ref-counting).
   # See http://clang.llvm.org/docs/AutomaticReferenceCounting.html.
   config("enable_arc") {
     common_flags = [ "-fobjc-arc" ]
     cflags_objc = common_flags
     cflags_objcc = common_flags
   }
 }