Optimize GLSL shaders.

Change-Id: I9a5e01bced63d8da0c61330a543a2b805388a59d
diff --git a/libs/hwui/Program.cpp b/libs/hwui/Program.cpp
index 2e1b9a0..25674c6 100644
--- a/libs/hwui/Program.cpp
+++ b/libs/hwui/Program.cpp
@@ -58,7 +58,6 @@
     mUse = false;
 
     position = addAttrib("position");
-    color = addUniform("color");
     transform = addUniform("transform");
 }
 
@@ -124,6 +123,10 @@
     glUniformMatrix4fv(transform, 1, GL_FALSE, &t.data[0]);
 }
 
+void Program::setColor(const float r, const float g, const float b, const float a) {
+    glUniform4f(getUniform("color"), r, g, b, a);
+}
+
 void Program::use() {
     glUseProgram(id);
     mUse = true;