Remove mac_sdk_min_build_override.

All projects that need to change the default mac min SDK now directly do so via
a GN arg.

Bug: chromium:740693
Change-Id: I99f04d482177e6ec8a5d1306f68cb2410b0beb0e
Reviewed-on: https://chromium-review.googlesource.com/566078
Commit-Queue: Erik Chen <erikchen@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#486514}

build/config/mac/mac_sdk.gni

@@ -73,7 +73,7 @@ xcode_version = _mac_sdk_result.xcode_version
 xcode_build = _mac_sdk_result.xcode_build
 machine_os_build = _mac_sdk_result.machine_os_build
 
-if (mac_sdk_version != mac_sdk_min_build_override &&
+if (mac_sdk_version != mac_sdk_min &&
     exec_script("//build/check_return_value.py",
                 [
                   "test",
@@ -89,7 +89,7 @@ if (mac_sdk_version != mac_sdk_min_build_override &&
   print(
       "          either upgrade Xcode to the latest version or install the Mac OS X")
   print(
-      "          $mac_sdk_min_build_override SDK. For more information, see https://crbug.com/620127.")
+      "          $mac_sdk_min SDK. For more information, see https://crbug.com/620127.")
   print()
   print(" Current SDK Version:   $mac_sdk_version")
   print(" Current Xcode Version: $xcode_version ($xcode_build)")

build/config/mac/mac_sdk_overrides.gni

@@ -5,18 +5,18 @@
 # This file contains arguments that subprojects may choose to override. It
 # asserts that those overrides are used, to prevent unused args warnings.
 
-# See https://bugs.chromium.org/p/webrtc/issues/detail?id=5453.
-# We can drop the rtc_require_mac_10_7_deployment flag when Chromium
-# also requires a 10.7 deployment target.
-import("//build_overrides/build.gni")
-
+_sdk_min_from_env = getenv("FORCE_MAC_SDK_MIN")
 declare_args() {
   # Minimum supported version of the Mac SDK.
-  mac_sdk_min = mac_sdk_min_build_override
+  if (_sdk_min_from_env == "") {
+    mac_sdk_min = "10.10"
+  } else {
+    mac_sdk_min = _sdk_min_from_env
+  }
 }
 
 # Always assert that mac_sdk_min is used on non-macOS platforms to prevent
 # unused args warnings.
 if (!is_mac) {
-  assert(mac_sdk_min == mac_sdk_min_build_override || true)
+  assert(mac_sdk_min == "10.10" || true)
 }

build_overrides/build.gni

@@ -2,17 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-# Several dependencies of Chrome require a different min sdk when built
-# as stand-alone projects. If this is ever not the case, these variables
-# can be removed.
-# See https://bugs.chromium.org/p/webrtc/issues/detail?id=5453.
-_sdk_min_from_env = getenv("FORCE_MAC_SDK_MIN")
-if (_sdk_min_from_env == "") {
-  mac_sdk_min_build_override = "10.10"
-} else {
-  mac_sdk_min_build_override = _sdk_min_from_env
-}
-
 # Variable that can be used to support multiple build scenarios, like having
 # Chromium specific targets in a client project's GN file etc.
 build_with_chromium = true