patch from chinmaygarde@ to make progress on mac, ios.

build/secondary/testing/gtest/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.
 
 config("gtest_config") {
   visibility = [
     ":*",
     "//testing/gmock:*",  # gmock also shares this config.
   ]
 
@@ skipping 78 matching lines @@
     "src/gtest-death-test.cc",
     "src/gtest-filepath.cc",
     "src/gtest-internal-inl.h",
     "src/gtest-port.cc",
     "src/gtest-printers.cc",
     "src/gtest-test-part.cc",
     "src/gtest-typed-test.cc",
     "src/gtest.cc",
   ]
 
-  if (is_mac) {
+  if (is_mac || is_ios) {
+    if (is_ios) {
+      set_sources_assignment_filter([])
+    }
     sources += [
       "../gtest_mac.h",
       "../gtest_mac.mm",
       "../platform_test_mac.mm",
     ]
+    set_sources_assignment_filter(sources_assignment_filter)
+  }
+
+  if (is_ios) {
+    sources += [
+      "../coverage_util_ios.cc",
+      "../coverage_util_ios.h",
+    ]
   }
 
   include_dirs = [ "." ]
 
   all_dependent_configs = [ ":gtest_config" ]
   public_configs = [ ":gtest_direct_config" ]
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
 
@@ skipping 11 matching lines @@
 source_set("gtest_main") {
   # TODO http://crbug.com/412064 enable this flag all the time.
   testonly = !is_component_build
   sources = [
     "src/gtest_main.cc",
   ]
   deps = [
     ":gtest",
   ]
 }