Add tools for code coverage support in iOS.

build/config/ios/ios_sdk.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/toolchain/toolchain.gni")
 
 declare_args() {
   # SDK path to use. When empty this will use the default SDK based on the
   # value of use_ios_simulator.
   ios_sdk_path = ""
@@ skipping 18 matching lines @@
   # "Organization Identifier" in Xcode). Code signing will fail if no mobile
   # provisioning for the selected code signing identify support that prefix.
   ios_app_bundle_id_prefix = "org.chromium"
 
   # If true, then allow using Xcode to automatically manage certificates. This
   # requires loading a separate Xcode project and enable automatically managed
   # certificates. When true, all test application will use the same bundle id
   # to avoid running out of certificates if using a free account.
   ios_automatically_manage_certs = true
 
+  # Enabling this option makes clang compile for profiling to gather code
+  # coverage metrics.
+  ios_enable_coverage = false
+
   # If non-empty, this list must contain valid cpu architecture, and the final
   # build will be a multi-architecture build (aka fat build) supporting the
   # main $target_cpu architecture and all of $additional_target_cpus.
   #
   # For example to build an application that will run on both arm64 and armv7
   # devices, you would use the following in args.gn file when running "gn args":
   #
   #   target_os = "ios"
   #   target_cpu = "arm64"
   #   additional_target_cpus = [ "arm" ]
@@ skipping 82 matching lines @@
     ios_code_signing_identity = _ios_identities[0]
   }
 
   if (ios_code_signing_identity == "") {
     print("Tried to prepare a device build without specifying a code signing")
     print("identity and could not detect one automatically either.")
     print("TIP: Simulator builds don't require code signing...")
     assert(false)
   }
 }