Add AlphaThreshold filter.

tests/GLProgramsTest.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 // This is a GPU-backend specific test. It relies on static intializers to work
 
@@ skipping 233 matching lines @@
 }
 
 #include "TestClassDef.h"
 DEFINE_GPUTESTCLASS("GLPrograms", GLProgramsTestClass, GLProgramsTest)
 
 // This is evil evil evil. The linker may throw away whole translation units as dead code if it
 // thinks none of the functions are called. It will do this even if there are static initializers
 // in the unit that could pass pointers to functions from the unit out to other translation units!
 // We force some of the effects that would otherwise be discarded to link here.
 
+#include "SkAlphaThresholdFilter.h"
 #include "SkLightingImageFilter.h"
 #include "SkMagnifierImageFilter.h"
 #include "SkColorMatrixFilter.h"
 #include "SkBitmapAlphaThresholdShader.h"
 
 void forceLinking();
 
 void forceLinking() {
     SkLightingImageFilter::CreateDistantLitDiffuse(SkPoint3(0,0,0), 0, 0, 0);
+    SkAlphaThresholdFilter alpha_thresh(SkRegion(), .5, .5);
     SkMagnifierImageFilter mag(SkRect::MakeWH(SK_Scalar1, SK_Scalar1), SK_Scalar1);
     GrConfigConversionEffect::Create(NULL,
                                      false,
                                      GrConfigConversionEffect::kNone_PMConversion,
                                      SkMatrix::I());
     SkScalar matrix[20];
     SkColorMatrixFilter cmf(matrix);
     SkBitmapAlphaThresholdShader::Create(SkBitmap(), SkRegion(), 0x80);
 }
 
 #endif