Split //ios/chrome/browser in multiple targets.

ios/chrome/browser/services/gcm/BUILD.gn

Index: ios/chrome/browser/services/gcm/BUILD.gn
diff --git a/ios/chrome/browser/services/gcm/BUILD.gn b/ios/chrome/browser/services/gcm/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..bf3fab903268b4d3a1b8ca64b34fe9ef80f4ae82
--- /dev/null
+++ b/ios/chrome/browser/services/gcm/BUILD.gn
@@ -0,0 +1,20 @@
+# Copyright 2016 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.
+
+source_set("gcm") {
+  sources = [
+    "ios_chrome_gcm_profile_service_factory.cc",
+    "ios_chrome_gcm_profile_service_factory.h",
+  ]
+  deps = [
+    "//base",
+    "//components/gcm_driver",
+    "//components/keyed_service/ios",
+    "//components/signin/core/browser",
+    "//ios/chrome/browser/browser_state",
+    "//ios/chrome/browser/signin",
+    "//ios/chrome/common",
+    "//ios/web",
+  ]
+}