Switch LevelDBWrapper::GetAll to use the new Mojo sync IPC mechanism.

content/renderer/dom_storage/local_storage_area.h

Index: content/renderer/dom_storage/local_storage_area.h
diff --git a/content/renderer/dom_storage/local_storage_area.h b/content/renderer/dom_storage/local_storage_area.h
index 506a1cab77f1b1e071c3efe2940073f81cde4cbf..963a49a10583f1239f426708c0aebab7587fea2a 100644
--- a/content/renderer/dom_storage/local_storage_area.h
+++ b/content/renderer/dom_storage/local_storage_area.h
@@ -48,6 +48,11 @@ class LocalStorageArea : public blink::WebStorageArea,
   void AllDeleted(const mojo::String& source) override;
 
  private:
+  // Synchronously fetches the origin's local storage data if it hasn't been
+  // fetched already.
+  void EnsureLoaded();
+
+  bool loaded_;
   url::Origin origin_;
   LevelDBWrapperPtr leveldb_;
   mojo::Binding<LevelDBObserver> binding_;