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/RenderEngine/Description.h b/services/surfaceflinger/RenderEngine/Description.h
index 3beffdf..cbac855 100644
--- a/services/surfaceflinger/RenderEngine/Description.h
+++ b/services/surfaceflinger/RenderEngine/Description.h
@@ -35,8 +35,6 @@
     friend class Program;
     friend class ProgramCache;
 
-    // value of the plane-alpha, between 0 and 1
-    GLclampf mPlaneAlpha;
     // whether textures are premultiplied
     bool mPremultipliedAlpha;
     // whether this layer is marked as opaque
@@ -46,8 +44,8 @@
     Texture mTexture;
     bool mTextureEnabled;
 
-    // color used when texturing is disabled
-    GLclampf mColor[4];
+    // color used when texturing is disabled or when setting alpha.
+    half4 mColor;
     // projection matrix
     mat4 mProjectionMatrix;
 
@@ -60,12 +58,11 @@
     Description();
     ~Description();
 
-    void setPlaneAlpha(GLclampf planeAlpha);
     void setPremultipliedAlpha(bool premultipliedAlpha);
     void setOpaque(bool opaque);
     void setTexture(const Texture& texture);
     void disableTexture();
-    void setColor(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha);
+    void setColor(const half4& color);
     void setProjectionMatrix(const mat4& mtx);
     void setColorMatrix(const mat4& mtx);
     const mat4& getColorMatrix() const;