EGL: Add stubs for EGL_ANDROID_blob_cache

This change adds a stub cache implementation that gets passed to the
underlying EGL implementation at initialization time.

Change-Id: I14437c5b6f91b7a34a19bb02ad802e6e54f88d2a
diff --git a/opengl/libs/Android.mk b/opengl/libs/Android.mk
index 3e66a13..5855b63 100644
--- a/opengl/libs/Android.mk
+++ b/opengl/libs/Android.mk
@@ -8,6 +8,7 @@
 
 LOCAL_SRC_FILES:= 	       \
 	EGL/egl_tls.cpp        \
+	EGL/egl_cache.cpp      \
 	EGL/egl_display.cpp    \
 	EGL/egl_object.cpp     \
 	EGL/egl.cpp 	       \
@@ -157,4 +158,3 @@
 include $(BUILD_SHARED_LIBRARY)
 
 include $(call all-makefiles-under,$(LOCAL_PATH))
-