Split //ios/public/provider/chrome/browser/* targets.

ios/public/provider/chrome/browser/omaha/BUILD.gn

Index: ios/public/provider/chrome/browser/omaha/BUILD.gn
diff --git a/ios/public/provider/chrome/browser/omaha/BUILD.gn b/ios/public/provider/chrome/browser/omaha/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..fbb35cd619c85d861dfb1dfb74243c707adf52d3
--- /dev/null
+++ b/ios/public/provider/chrome/browser/omaha/BUILD.gn
@@ -0,0 +1,26 @@
+# 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("omaha") {
+  sources = [
+    "omaha_service_provider.h",
+    "omaha_service_provider.mm",
+    "omaha_xml_writer.h",
+  ]
+  deps = [
+    "//base",
+    "//url",
+  ]
+}
+
+source_set("test_support") {
+  testonly = true
+  sources = [
+    "test_omaha_service_provider.h",
+    "test_omaha_service_provider.mm",
+  ]
+  deps = [
+    "//ios/public/provider/chrome/browser/omaha",
+  ]
+}