Add a dedicated "optimize_speed" config to GN.

third_party/opus/BUILD.gn

 # Copyright 2014 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/arm.gni")
 import("//testing/test.gni")
 
 # If fixed point implementation shall be used (otherwise float).
 use_opus_fixed_point = current_cpu == "arm" || current_cpu == "arm64"
 
@@ skipping 99 matching lines @@
 
   if (is_posix && !is_android) {
     # Suppress a warning given by opus_decoder.c that tells us
     # optimizations are turned off.
     cflags += [ "-Wno-#pragma-messages" ]
   }
 
   if (!is_debug && is_posix &&
       (current_cpu == "arm" || current_cpu == "arm64")) {
     configs -= [ "//build/config/compiler:default_optimization" ]
-    configs += [ "//build/config/compiler:optimize_max" ]
+
+    # TODO(crbug.com/621335) Rework this so that we don't have the confusion
+    # between "optimize_speed" and "optimize_max".
+    configs += [ "//build/config/compiler:optimize_speed" ]
   }
 
   if (use_opus_fixed_point) {
     sources += gypi_values.opus_fixed_sources
 
     defines += [ "FIXED_POINT" ]
 
     include_dirs += [ "src/silk/fixed" ]
   } else {
     sources += gypi_values.opus_float_sources
@@ skipping 156 matching lines @@
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [
     "//build/config/compiler:no_chromium_code",
     ":opus_test_config",
   ]
 
   deps = [
     ":opus",
   ]
 }