Reland of Ensure that builders that use goma strip absolute paths 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 76 matching lines @@
   # AFDO (Automatic Feedback Directed Optimizer) is a form of profile-guided
   # optimization that GCC supports. It used by ChromeOS in their official
   # builds. To use it, set auto_profile_path to the path to a file containing
   # the needed gcov profiling data.
   auto_profile_path = ""
 
   # Optimize for coverage guided fuzzing (balance between speed and number of
   # branches)
   optimize_for_fuzzing = false
 
-  # Optimize symbol files for maximizing goma cache hit rate.
+  # Optimize symbol files for maximizing goma cache hit rate. This isn't
+  # on by default when goma is enabled because setting this to true may make
+  # it harder to debug binaries.
   strip_absolute_paths_from_debug_symbols = false
 }
 
 if (is_clang && !is_nacl) {
   update_args = [ "--print-revision" ]
   if (llvm_force_head_revision) {
     update_args += [ "--llvm-force-head-revision" ]
   }
   clang_revision =
       exec_script("//tools/clang/scripts/update.py", update_args, "trim string")
@@ skipping 1623 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
   }
 }