Move AccessTokenStore to Content API, now that it is a pure-virtual class.

content/content_browser.gypi

Index: content/content_browser.gypi
diff --git a/content/content_browser.gypi b/content/content_browser.gypi
index 2cb61fb40eb91352325cd0ec4ff9277322d85b55..a3ebd47d0615682243d87e2c508d58d09d320f4c 100644
--- a/content/content_browser.gypi
+++ b/content/content_browser.gypi
@@ -25,6 +25,8 @@
     '<(INTERMEDIATE_DIR)',
   ],
   'sources': [
+    'public/browser/access_token_store.cc',
+    'public/browser/access_token_store.h',
     'public/browser/browser_context.h',
     'public/browser/browser_main_parts.h',
     'public/browser/browser_message_filter.cc',
@@ -221,8 +223,6 @@
     'browser/gamepad/gamepad_provider.h',
     'browser/gamepad/gamepad_service.cc',
     'browser/gamepad/gamepad_service.h',
-    'browser/geolocation/access_token_store.cc',
-    'browser/geolocation/access_token_store.h',
     'browser/geolocation/arbitrator_dependency_factory.cc',
     'browser/geolocation/arbitrator_dependency_factory.h',
     'browser/geolocation/core_location_data_provider_mac.h',