[ObjC ARC] Converts ios/chrome/test/earl_grey:ios_chrome_device_check_egtests to ARC.

ios/chrome/test/earl_grey/BUILD.gn

Index: ios/chrome/test/earl_grey/BUILD.gn
diff --git a/ios/chrome/test/earl_grey/BUILD.gn b/ios/chrome/test/earl_grey/BUILD.gn
index c5b78e93172c839a3b81a3df08e781a1cadaf1fc..a7d4081dfc308d88d9272f41cf1284efc60a1c83 100644
--- a/ios/chrome/test/earl_grey/BUILD.gn
+++ b/ios/chrome/test/earl_grey/BUILD.gn
@@ -99,9 +99,17 @@ chrome_ios_eg_test("ios_chrome_multitasking_egtests") {
 }
 
 chrome_ios_eg_test("ios_chrome_device_check_egtests") {

[sdefresne, 2017/05/16 08:26:20]

I think a better change would be to allow overriding "configs" for
"chrome_ios_eg_tests" template. You should add the following to
ios/chrome/test/earl_grey/chrome_ios_eg_test.gni, below the definition of
"chrome_ios_eg_test" template:

set_defaults("chrome_ios_eg_test") {
  configs = default_executable_configs
}

That should be enough to allow you to change this file to the following:

chrome_ios_eg_test("ios_chrome_device_check_egtests") {
  configs += [ "//build/config/compiler:enable_arc" ]
  sources = [
    "device_check_egtest.mm",
  ]
  deps = [
    ":test_support",
    "//ios/third_party/earl_grey",
    "//url",
  ]
}

[liaoyuke, 2017/05/16 16:08:31]

Hi Sylvain,

Thank you for the detailed explanation!

I've updated the CL according to your comments, however, it seems that [
"//build/config/compiler:enable_arc" ] still doesn't apply to
"device_check_egtest.mm".

I debugged a little bit, but couldn't understand, do you have any thoughts?

+  deps = [
+    ":device_check_sources",
+  ]
+}
+
+source_set("device_check_sources") {
+  configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
     "device_check_egtest.mm",

[sdefresne, 2017/05/16 08:27:17]

This CL needs to add guards to "device_check_egtest.mm" file to prevent
compiling it without ARC.

[liaoyuke, 2017/05/16 16:08:31]

Done.

   ]
+  testonly = true
   deps = [
     ":test_support",
     "//ios/third_party/earl_grey",