Remove the enable_mac_keystone build flag.

enable_mac_keystone was a global flag in the build directory that's only used
by 4 total checks in 2 BUILD files. I'm trying to clean up the global build
flags.

Changes the checks to just check for mac Chrome branded builds. The previous
code additionally checked for "official" builds, but "official" is actually an
optimization level that I don't think is relevant to whether there are
installer scripts included in the bundle.

BUG=671706

Review-Url: https://codereview.chromium.org/2558973003
Cr-Commit-Position: refs/heads/master@{#437687}

build/config/features.gni

@@ -91,8 +91,6 @@ enable_rlz = is_chrome_branded && enable_rlz_support
 enable_chromevox_next = false
 
 enable_configuration_policy = !is_ios
-
-enable_mac_keystone = is_mac && is_chrome_branded && is_official_build
 #
 # =============================================
 #   PLEASE DO NOT ADD MORE FLAGS TO THIS FILE

chrome/BUILD.gn

@@ -498,7 +498,7 @@ if (is_win) {
   tweak_info_plist("chrome_app_plist") {
     info_plist = "app/app-Info.plist"
     _keystone_arg = "0"
-    if (enable_mac_keystone) {
+    if (is_chrome_branded) {
       _keystone_arg = "1"
     }
     args = [
@@ -761,7 +761,7 @@ if (is_win) {
       "//chrome/app_shim:app_mode_loader",
     ]
 
-    if (enable_mac_keystone) {
+    if (is_chrome_branded) {
       sources += [
         "browser/mac/keystone_promote_postflight.sh",
         "browser/mac/keystone_promote_preflight.sh",
@@ -900,7 +900,7 @@ if (is_win) {
     }
   }
 
-  if (enable_mac_keystone) {
+  if (is_chrome_branded) {
     action("keystone_registration_framework") {
       script = "//chrome/tools/build/mac/copy_keystone_framework.py"
 

chrome/installer/mac/BUILD.gn

@@ -69,7 +69,7 @@ copy("copies") {
     "sign_installer_tools.sh",
   ]
 
-  if (enable_mac_keystone) {
+  if (is_chrome_branded) {
     sources += [ "keystone_install.sh" ]
   }