Implement highQualityFilter16 so GM doesn't crash when you give it resources.

src/core/SkBitmapProcState.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.
  */
 #include "SkBitmapProcState.h"
 #include "SkColorPriv.h"
 #include "SkFilterProc.h"
@@ skipping 358 matching lines @@
         // downgrade to bilerp.
 
         // NOTE: Might need to be careful here in the future when we want
         // to have the platform proc have a shot at this; it's possible that
         // the chooseBitmapFilterProc will fail to install a shader but a
         // platform-specific one might succeed, so it might be premature here
         // to fall back to bilerp.  This needs thought.
 
         SkASSERT(fInvType > SkMatrix::kTranslate_Mask);
 
-        fShaderProc32 = this->chooseBitmapFilterProc();
-        if (!fShaderProc32) {
+        if (!this->setBitmapFilterProcs()) {
             fFilterLevel = SkPaint::kLow_FilterLevel;
         }
     }
 
     if (SkPaint::kLow_FilterLevel == fFilterLevel) {
         // Only try bilerp if the matrix is "interesting" and
         // the image has a suitable size.
 
         if (fInvType <= SkMatrix::kTranslate_Mask ||
                 !valid_for_filtering(fBitmap->width() | fBitmap->height())) {
             fFilterLevel = SkPaint::kNone_FilterLevel;
         }
     }
 
     // At this point, we know exactly what kind of sampling the per-scanline
     // shader will perform.
 
     fMatrixProc = this->chooseMatrixProc(trivialMatrix);
     if (NULL == fMatrixProc) {
         return false;
     }
 
     ///////////////////////////////////////////////////////////////////////
 
     // No need to do this if we're doing HQ sampling; if filter quality is
     // still set to HQ by the time we get here, then we must have installed
-    // the shader proc above and can skip all this.
+    // the shader procs above and can skip all this.
 
     if (fFilterLevel < SkPaint::kHigh_FilterLevel) {
 
         int index = 0;
         if (fAlphaScale < 256) {  // note: this distinction is not used for D16
             index |= 1;
         }
         if (fInvType <= (SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask)) {
             index |= 2;
         }
@@ skipping 531 matching lines @@
     } else {
         size >>= 2;
     }
 
     if (fFilterLevel != SkPaint::kNone_FilterLevel) {
         size >>= 1;
     }
 
     return size;
 }