Image Filters: refactor all CPU input processing into a filterInput helper function.

src/effects/SkMergeImageFilter.cpp

 /*
  * Copyright 2012 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkMergeImageFilter.h"
 #include "SkCanvas.h"
 #include "SkDevice.h"
@@ skipping 63 matching lines @@
     if (nullptr == dst) {
         return false;
     }
     SkCanvas canvas(dst);
     SkPaint paint;
 
     bool didProduceResult = false;
     int inputCount = countInputs();
     for (int i = 0; i < inputCount; ++i) {
         SkBitmap tmp;
-        const SkBitmap* srcPtr;
+        SkBitmap input = src;
         SkIPoint pos = SkIPoint::Make(0, 0);
-        SkImageFilter* filter = getInput(i);
-        if (filter) {
-            if (!filter->filterImage(proxy, src, ctx, &tmp, &pos)) {
-                continue;
-            }
-            srcPtr = &tmp;
-        } else {
-            srcPtr = &src;
+        if (!this->filterInput(i, proxy, src, ctx, &input, &pos)) {
+            continue;
         }
-
         if (fModes) {
             paint.setXfermodeMode((SkXfermode::Mode)fModes[i]);
         } else {
             paint.setXfermode(nullptr);
         }
-        canvas.drawSprite(*srcPtr, pos.x() - x0, pos.y() - y0, &paint);
+        canvas.drawSprite(input, pos.x() - x0, pos.y() - y0, &paint);
         didProduceResult = true;
     }
 
     if (!didProduceResult)
         return false;
 
     offset->fX = bounds.left();
     offset->fY = bounds.top();
     *result = dst->accessBitmap(false);
     return true;
@@ skipping 40 matching lines @@
     for (int i = 0; i < this->countInputs(); ++i) {
         SkImageFilter* filter = this->getInput(i);
         str->appendf("%d: (", i);
         filter->toString(str);
         str->appendf(")");
     }
 
     str->append(")");
 }
 #endif