Minimal patch to enable jumbo builds for blink core

build/config/jumbo.gni

 # Copyright 2017 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/split_static_library.gni")  # When someone uses that target_type
 
 declare_args() {
   # If true, use a jumbo build (files compiled together) to speed up
-  # compilation.
-  use_jumbo_build = false
+  # compilation. Enabled by default for everything official builds and
+  # Android+gcc builds because of a warning that prevents builds.
+  use_blink_jumbo_build = !is_official_build && !(is_android && !is_clang)
 
   # A target to exclude from jumbo builds, for optimal round trip time
   # when frequently changing a single cpp file.
   jumbo_build_excluded = ""
 
   # How many files to group at most. Smaller numbers give more
   # parallellism, higher numbers give less total CPU usage. Higher
   # numbers also give longer single-file recompilation times.
   #
   # Recommendations:
@@ skipping 116 matching lines @@
     forward_variables_from(invoker, "*", variables_to_not_forward)
   }
 }
 
 set_defaults("jumbo_target") {
   # This sets the default list of configs when the content_source_set target
   # is defined. The default_compiler_configs comes from BUILDCONFIG.gn and
   # is the list normally applied to static libraries and source sets.
   configs = default_compiler_configs
 }