Add toString methods to SkImageFilter-derived classes

src/effects/SkComposeImageFilter.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkComposeImageFilter.h"
 #include "SkReadBuffer.h"
@@ skipping 22 matching lines @@
     SkImageFilter* inner = getInput(1);
 
     SkIRect tmp;
     return inner->filterBounds(src, ctm, &tmp) && outer->filterBounds(tmp, ctm, dst);
 }
 
 SkFlattenable* SkComposeImageFilter::CreateProc(SkReadBuffer& buffer) {
     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 2);
     return SkComposeImageFilter::Create(common.getInput(0), common.getInput(1));
 }
+
+#ifndef SK_IGNORE_TO_STRING
+void SkComposeImageFilter::toString(SkString* str) const {
+    SkImageFilter* outer = getInput(0);
+    SkImageFilter* inner = getInput(1);
+
+    str->appendf("SkComposeImageFilter: (");
+
+    str->appendf("outer: ");
+    outer->toString(str);
+
+    str->appendf("inner: ");
+    inner->toString(str);
+
+    str->appendf(")");
+}
+#endif