Add toString methods to SkImageFilter-derived classes

src/effects/SkOffsetImageFilter.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 "SkOffsetImageFilter.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 90 matching lines @@
 void SkOffsetImageFilter::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writePoint(fOffset);
 }
 
 SkOffsetImageFilter::SkOffsetImageFilter(SkScalar dx, SkScalar dy, SkImageFilter* input,
                                          const CropRect* cropRect, uint32_t uniqueID)
   : INHERITED(1, &input, cropRect, uniqueID) {
     fOffset.set(dx, dy);
 }
+
+#ifndef SK_IGNORE_TO_STRING
+void SkOffsetImageFilter::toString(SkString* str) const {
+    str->appendf("SkOffsetImageFilter: (");
+    str->appendf("offset: (%f, %f) ", fOffset.fX, fOffset.fY);
+    str->append("input: (");
+    if (this->getInput(0)) {
+        this->getInput(0)->toString(str);
+    }
+    str->append("))");
+}
+#endif