Use third_party/custom_tabs_client as the src for customtabs library

third_party/custom_tabs_client/BUILD.gn

Index: third_party/custom_tabs_client/BUILD.gn
diff --git a/third_party/custom_tabs_client/BUILD.gn b/third_party/custom_tabs_client/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..858b002a7a2171c1ba4b01cfa2688745381e6f36
--- /dev/null
+++ b/third_party/custom_tabs_client/BUILD.gn
@@ -0,0 +1,24 @@
+# Copyright 2015 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/android/rules.gni")
+
+# GYP: //third_party/custom_tabs_client/custom_tabs_client.gyp:custom_tabs_support_lib
+android_library("custom_tabs_support_lib") {
+  srcjar_deps = [ ":custom_tabs_service_aidl" ]
+  deps = [
+    "//third_party/android_tools:android_support_v13_java",
+  ]
+  DEPRECATED_java_in_dir = "src/customtabs/src/android/support/customtabs/"
+}
+
+# GYP: //third_party/custom_tabs_client/custom_tabs_client.gyp:custom_tabs_service_aidl
+android_aidl("custom_tabs_service_aidl") {
+  import_include = "src/customtabs/src"
+  interface_file = "common.aidl"
+  sources = [
+    "src/customtabs/src/android/support/customtabs/ICustomTabsCallback.aidl",
+    "src/customtabs/src/android/support/customtabs/ICustomTabsService.aidl",
+  ]
+}