Add support for loading API keys from Info.plist on iOS and macOS.

google_apis/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.
 
 import("//build/config/features.gni")
 import("//testing/test.gni")
 
 declare_args() {
   # You can set the variable 'use_official_google_api_keys' to true
   # to use the Google-internal file containing official API keys
@@ skipping 155 matching lines @@
         "drive/request_sender.cc",
         "drive/request_sender.h",
         "drive/request_util.cc",
         "drive/request_util.h",
         "drive/task_util.cc",
         "drive/task_util.h",
         "drive/time_util.cc",
         "drive/time_util.h",
       ]
     }
+
+    if (is_mac || is_ios) {
+      set_sources_assignment_filter([])
+
+      sources += [
+        "google_api_keys_mac.h",
+        "google_api_keys_mac.mm",
+      ]
+
+      set_sources_assignment_filter(sources_assignment_filter)
+    }
   }
 }
 
 google_apis_tmpl("google_apis") {
   deps = [
     "//net",
   ]
 }
 
 static_library("test_support") {
@@ skipping 67 matching lines @@
       "drive/base_requests_unittest.cc",
       "drive/drive_api_parser_unittest.cc",
       "drive/drive_api_requests_unittest.cc",
       "drive/drive_api_url_generator_unittest.cc",
       "drive/files_list_request_runner_unittest.cc",
       "drive/request_sender_unittest.cc",
       "drive/request_util_unittest.cc",
       "drive/time_util_unittest.cc",
     ]
   }
+
+  if (is_mac || is_ios) {
+    set_sources_assignment_filter([])
+    sources += [ "google_api_keys_mac_unittest.mm" ]
+    set_sources_assignment_filter(sources_assignment_filter)
+
+    deps += [ "//third_party/ocmock" ]
+  }
 }