Cleaner fall-back stack capture for --enable-heap-profiling=native.

build/config/compiler/compiler.gni

 # Copyright 2015 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/arm.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/compiler/pgo/pgo.gni")
 import("//build/config/sanitizers/sanitizers.gni")
@@ skipping 67 matching lines @@
   }
 } else {
   # 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).
   enabled_frame_pointers =
       using_sanitizer || enable_profiling || is_debug || current_cpu == "arm64"
 }
 
-# Unwinding with frame pointers requires that frame pointers are enabled by
-# default for most translation units, and that the architecture isn't thumb, as
-# frame pointers are not correctly emitted for thumb.
-if (enabled_frame_pointers && !(current_cpu == "arm" && arm_use_thumb)) {
-  can_unwind_with_frame_pointers = true
+# Unwinding with frame pointers requires that they are enabled by default for
+# most translation units, that they are emitted correctly, and that the
+# compiler or platform provides a way to access them.
+if (current_cpu == "arm" && arm_use_thumb) {
+  # ARM Thumb builds do not emit frame pointers correctly.
+  can_unwind_with_frame_pointers = false
+} else if (is_win) {
+  # Windows 32-bit does provide frame pointers, but the compiler does not
+  # provide intrinsics to access them, so we don't use them.
+  can_unwind_with_frame_pointers = false
 } else {
-  can_unwind_with_frame_pointers = false
+  can_unwind_with_frame_pointers = enabled_frame_pointers
 }
 
 declare_args() {
   # Whether or not the official builds should be built with full WPO. Enabled by
   # default for the PGO and the x64 builds.
   if (chrome_pgo_phase > 0) {
     full_wpo_on_official = true
   } else {
     full_wpo_on_official = false
   }
@@ skipping 51 matching lines @@
 }
 
 # Assert that the configuration isn't going to hit https://crbug.com/648948.
 assert(ignore_elf32_limitations || !is_android ||
            (android_64bit_target_cpu && !build_apk_secondary_abi) ||
            is_component_build || symbol_level < 2,
        "Android 32-bit non-component builds cannot have symbol_level=2 " +
            "due to 4GiB file size limit, see https://crbug.com/648948. " +
            "If you really want to try this out, " +
            "set ignore_elf32_limitations=true.")