Adds EngineGeolocationFeature for Blimp Geolocation project.

blimp/engine/session/blimp_engine_session.h

Index: blimp/engine/session/blimp_engine_session.h
diff --git a/blimp/engine/session/blimp_engine_session.h b/blimp/engine/session/blimp_engine_session.h
index 960ce71dcc2fd53a0e29f827dbc335a035f84319..75ef9737422121e8d019da23235600401dcf2f40 100644
--- a/blimp/engine/session/blimp_engine_session.h
+++ b/blimp/engine/session/blimp_engine_session.h
@@ -14,6 +14,7 @@
 #include "blimp/common/proto/blimp_message.pb.h"
 #include "blimp/engine/feature/engine_render_widget_feature.h"
 #include "blimp/engine/feature/engine_settings_feature.h"
+#include "blimp/engine/feature/geolocation/engine_geolocation_feature.h"
 #include "blimp/net/blimp_message_processor.h"
 #include "blimp/net/connection_error_observer.h"
 #include "content/public/browser/invalidate_type.h"
@@ -95,6 +96,9 @@ class BlimpEngineSession
     return blob_channel_sender_.get();
   }
 
+  // Returns a pointer to the Geolocation feature.
+  EngineGeolocationFeature* GetGeolocationFeature();
+
   // Gets Engine's listening port. Invokes callback with the allocated port.
   void GetEnginePortForTesting(const GetPortCallback& callback);
 
@@ -204,6 +208,9 @@ class BlimpEngineSession
   // |blob_delegate_|.
   std::unique_ptr<BlobChannelSender> blob_channel_sender_;
 
+  // Handles all incoming and outgoing messages related to Geolocation.
+  EngineGeolocationFeature geolocation_feature_;
+
   // Container for connection manager, authentication handler, and
   // browser connection handler. The components run on the I/O thread, and
   // this object is destroyed there.