Added native functionality to create a color layer.

Added a new layer that can draw a specified color and specified
alpha. This will replace creating a dim layer and allow any colors,
not just black, to be set for this layer.

Test: Added tests to Transaction_test.cpp to test with a color
      and a color layer with alpha.

Change-Id: I00a38d1bbc01093026f088c3347454281bdc2b8c
diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk
index 38529b6..1f4427a 100644
--- a/services/surfaceflinger/Android.mk
+++ b/services/surfaceflinger/Android.mk
@@ -14,7 +14,7 @@
     FrameTracker.cpp \
     GpuService.cpp \
     Layer.cpp \
-    LayerDim.cpp \
+    ColorLayer.cpp \
     LayerRejecter.cpp \
     LayerVector.cpp \
     MessageQueue.cpp \