Android: Do not build files not needed on the platform.

chrome/browser/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/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//third_party/protobuf/proto_library.gni")
 
@@ skipping 1086 matching lines @@
     "//ui/gfx",
   ]
 
   if (!is_ios) {
     deps += [
       "//components/sessions:test_support",
       "//google_apis:test_support",
     ]
   }
 
+  if (is_android) {
+    sources -= [
+      "sessions/session_service_test_helper.cc",
+      "sessions/session_service_test_helper.h",
+      "ui/webui/signin/login_ui_test_utils.cc",
+      "ui/webui/signin/login_ui_test_utils.h",
+    ]
+  }
+
   if (enable_extensions) {
     sources += [
       "extensions/extension_action_test_util.cc",
       "extensions/extension_action_test_util.h",
     ]
     deps += [ "//extensions:test_support" ]
   }
 
   if (is_chromeos) {
     sources += [
@@ skipping 129 matching lines @@
         rebase_path(gypi_values.chrome_browser_rlz_sources, ".", "//chrome")
     deps = [
       "//components/google/core/browser",
       "//components/omnibox/browser",
       "//components/rlz",
       "//components/search_engines",
       "//rlz:rlz_lib",
     ]
   }
 }