Remove unused libxml dependencies.

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("//extensions/features/features.gni")
 import("//testing/test.gni")
 
 declare_args() {
   # You can set the variable 'use_official_google_api_keys' to true
@@ skipping 120 matching lines @@
 
     configs += [
       ":key_defines",
       "//build/config/compiler:no_size_t_to_int_warning",
     ]
 
     deps = [
       "//base",
       "//base/third_party/dynamic_annotations",
       "//crypto",
-      "//third_party/libxml",
     ]
 
     if (defined(invoker.deps)) {
       deps += invoker.deps
     }
 
     if (enable_extensions) {
       sources += [
         "drive/auth_service.cc",
         "drive/auth_service.h",
@@ skipping 125 matching lines @@
   }
 
   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" ]
   }
 }