Add some .h files under chrome/browser to .gn files.

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("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 2966 matching lines @@
       "android/signin/signin_manager_android.cc",
       "android/signin/signin_manager_android.h",
       "android/signin/signin_promo_util_android.cc",
       "android/signin/signin_promo_util_android.h",
       "android/tab_android.cc",
       "android/tab_android.h",
       "android/tab_state.cc",
       "android/tab_state.h",
       "android/tab_web_contents_delegate_android.cc",
       "android/tab_web_contents_delegate_android.h",
+      "android/thumbnail/scoped_ptr_expiring_cache.h",
       "android/thumbnail/thumbnail.cc",
       "android/thumbnail/thumbnail.h",
       "android/thumbnail/thumbnail_cache.cc",
       "android/thumbnail/thumbnail_cache.h",
       "android/url_utilities.cc",
       "android/url_utilities.h",
       "android/usb/web_usb_chooser_service_android.cc",
       "android/usb/web_usb_chooser_service_android.h",
       "android/voice_search_tab_helper.cc",
       "android/voice_search_tab_helper.h",
@@ skipping 1690 matching lines @@
       "media/pepper_cdm_test_constants.cc",
       "media/pepper_cdm_test_constants.h",
     ]
   }
 }
 
 service_manifest("preferences_forwarder_manifest") {
   name = "preferences_forwarder"
   source = "prefs/forwarder_manifest.json"
 }