Moved GrGLFragmentProcessor definition to its own file

BUG=skia:

Review URL: https://codereview.chromium.org/1246193002
diff --git a/src/gpu/effects/GrSimpleTextureEffect.cpp b/src/gpu/effects/GrSimpleTextureEffect.cpp
index c1b2811..8e6243d 100644
--- a/src/gpu/effects/GrSimpleTextureEffect.cpp
+++ b/src/gpu/effects/GrSimpleTextureEffect.cpp
@@ -9,7 +9,7 @@
 #include "GrInvariantOutput.h"
 #include "GrTexture.h"
 #include "gl/GrGLCaps.h"
-#include "gl/GrGLProcessor.h"
+#include "gl/GrGLFragmentProcessor.h"
 #include "gl/GrGLTexture.h"
 #include "gl/builders/GrGLProgramBuilder.h"