arc-app-launcher: Minimal support for ARC app launcher.

chromeos/arc/bridge/common/arc_host_messages.h

Index: chromeos/arc/bridge/common/arc_host_messages.h
diff --git a/chromeos/arc/bridge/common/arc_host_messages.h b/chromeos/arc/bridge/common/arc_host_messages.h
index a04efd20ea568acf5f27e17c9694ec26bf9bd043..80772174d23bc9ad675eb6ae1bcd55dedebe30bc 100644
--- a/chromeos/arc/bridge/common/arc_host_messages.h
+++ b/chromeos/arc/bridge/common/arc_host_messages.h
@@ -5,8 +5,28 @@
 // Messages sent from the host to the ARC instance
 // Multiply-included message file, hence no include guard.
 
+#include "chromeos/chromeos_export.h"
 #include "ipc/ipc_message_macros.h"
 
+#include <string>
+#include <vector>
+
+// Export IPC messages.
+#undef IPC_MESSAGE_EXPORT
+#define IPC_MESSAGE_EXPORT CHROMEOS_EXPORT
+
 #define IPC_MESSAGE_START ArcInstanceHostMsgStart
 
 IPC_MESSAGE_CONTROL0(ArcInstanceHostMsg_InstanceReady)
+
+// Sends available apps on Android side.
+IPC_MESSAGE_CONTROL2(ArcInstanceHostMsg_AppsRefreshed,
+                     std::vector<std::string>, /* labels */
+                     std::vector<std::string> /* packages */)
+
+// Sends app icon data for specific scale factor.
+IPC_MESSAGE_CONTROL4(ArcInstanceHostMsg_AppIcon,
+                     std::string, /* package */
+                     std::string, /* activity */
+                     int,         /* scale factor */
+                     std::vector<uint8_t> /* icon data */)