Put all of ValueStore in value_store namespace.

This is in preparation for https://crrev.com/c/3134756 which moves
extensions/browser/value_store to components/value_store.

This change is mostly involves adding 'value_store::' in lots of places.
In files where 'ValueStore::*' is used a lot I've added
'using value_store::ValueStore;' to avoid writing
value_store::ValueStore lots of times.

Bug: 1226956
Change-Id: I5c21754532b27bd5ab07d099bddb17833b9f7733
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3128960
Commit-Queue: Louise Brett <[email protected]>
Reviewed-by: Victor Vianna <[email protected]>
Reviewed-by: Xiaohui Chen <[email protected]>
Reviewed-by: Sean Topping <[email protected]>
Reviewed-by: Devlin <[email protected]>
Reviewed-by: Anqing Zhao <[email protected]>
Reviewed-by: Glen Robertson <[email protected]>
Cr-Commit-Position: refs/heads/main@{#919629}
diff --git a/extensions/browser/mock_extension_system.h b/extensions/browser/mock_extension_system.h
index 5f251675..d6d7263 100644
--- a/extensions/browser/mock_extension_system.h
+++ b/extensions/browser/mock_extension_system.h
@@ -39,7 +39,7 @@
   UserScriptManager* user_script_manager() override;
   StateStore* state_store() override;
   StateStore* rules_store() override;
-  scoped_refptr<ValueStoreFactory> store_factory() override;
+  scoped_refptr<value_store::ValueStoreFactory> store_factory() override;
   InfoMap* info_map() override;
   QuotaService* quota_service() override;
   AppSorting* app_sorting() override;