migrate skpdiff to tools

experimental/skpdiff/SkImageDiffer.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 "SkImageDecoder.h"
-
-#include "SkImageDiffer.h"
-#include "skpdiff_util.h"
-
-
-SkImageDiffer::SkImageDiffer()
-    : fIsGood(true) {
-
-}
-
-SkImageDiffer::~SkImageDiffer() {
-
-}
-
-int SkImageDiffer::queueDiffOfFile(const char baseline[], const char test[]) {
-    SkBitmap baselineBitmap;
-    SkBitmap testBitmap;
-    if (!SkImageDecoder::DecodeFile(baseline, &baselineBitmap)) {
-        SkDebugf("Failed to load bitmap \"%s\"\n", baseline);
-        return -1;
-    }
-    if (!SkImageDecoder::DecodeFile(test, &testBitmap)) {
-        SkDebugf("Failed to load bitmap \"%s\"\n", test);
-        return -1;
-    }
-    return this->queueDiff(&baselineBitmap, &testBitmap);
-}