Add toString methods to SkImageFilter-derived classes

gm/imagefiltersgraph.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 
 #include "SkArithmeticMode.h"
@@ skipping 44 matching lines @@
         SkCanvas canvas(device);
         SkPaint paint;
         paint.setXfermodeMode(SkXfermode::kSrc_Mode);
         canvas.drawBitmap(source, fDX - bounds.left(), fDY - bounds.top(), &paint);
         *dst = device->accessBitmap(false);
         offset->fX += bounds.left();
         offset->fY += bounds.top();
         return true;
     }
 
+    SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SimpleOffsetFilter);
 
 protected:
     virtual void flatten(SkWriteBuffer& buffer) const SK_OVERRIDE {
         this->INHERITED::flatten(buffer);
         buffer.writeScalar(fDX);
         buffer.writeScalar(fDY);
     }
 
 private:
     SimpleOffsetFilter(SkScalar dx, SkScalar dy, SkImageFilter* input)
         : SkImageFilter(1, &input), fDX(dx), fDY(dy) {}
 
     SkScalar fDX, fDY;
 
     typedef SkImageFilter INHERITED;
 };
 
 static SimpleOffsetFilter::Registrar gReg;
 
 SkFlattenable* SimpleOffsetFilter::CreateProc(SkReadBuffer& buffer) {
     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
     SkScalar dx = buffer.readScalar();
     SkScalar dy = buffer.readScalar();
     return Create(dx, dy, common.getInput(0));
 }
 
+#ifndef SK_IGNORE_TO_STRING
+void SimpleOffsetFilter::toString(SkString* str) const {
+    str->appendf("SimpleOffsetFilter: (");
+    str->append(")");
+}
+#endif
+
 class ImageFiltersGraphGM : public skiagm::GM {
 public:
     ImageFiltersGraphGM() {}
 
 protected:
     virtual uint32_t onGetFlags() const SK_OVERRIDE {
         return kSkipTiled_Flag;
     }
 
     virtual SkString onShortName() {
@@ skipping 117 matching lines @@
 
 private:
     typedef GM INHERITED;
     SkBitmap fBitmap;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 static skiagm::GM* MyFactory(void*) { return new ImageFiltersGraphGM; }
 static skiagm::GMRegistry reg(MyFactory);