remove unused SkBitmap::scrollRect API

src/core/SkBitmap_scroll.cpp

-
-/*
- * Copyright 2011 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 "SkRegion.h"
-
-bool SkBitmap::scrollRect(const SkIRect* subset, int dx, int dy,
-                          SkRegion* inval) const
-{
-    if (this->isImmutable() || kUnknown_SkColorType == this->colorType()) {
-        return false;
-    }
-
-    if (subset) {
-        SkBitmap tmp;
-
-        return  this->extractSubset(&tmp, *subset) &&
-                // now call again with no rectangle
-                tmp.scrollRect(NULL, dx, dy, inval);
-    }
-
-    int shift = this->bytesPerPixel() >> 1;
-    int width = this->width();
-    int height = this->height();
-
-    // check if there's nothing to do
-    if ((dx | dy) == 0 || width <= 0 || height <= 0) {
-        if (inval) {
-            inval->setEmpty();
-        }
-        return true;
-    }
-
-    // compute the inval region now, before we see if there are any pixels
-    if (inval) {
-        SkIRect r;
-
-        r.set(0, 0, width, height);
-        // initial the region with the entire bounds
-        inval->setRect(r);
-        // do the "scroll"
-        r.offset(dx, dy);
-
-        // check if we scrolled completely away
-        if (!SkIRect::Intersects(r, inval->getBounds())) {
-            // inval has already been updated...
-            return true;
-        }
-
-        // compute the dirty area
-        inval->op(r, SkRegion::kDifference_Op);
-    }
-
-    SkAutoLockPixels    alp(*this);
-    // if we have no pixels, just return (inval is already updated)
-    // don't call readyToDraw(), since we don't require a colortable per se
-    if (this->getPixels() == NULL) {
-        return true;
-    }
-
-    char*       dst = (char*)this->getPixels();
-    const char* src = dst;
-    int         rowBytes = (int)this->rowBytes();    // need rowBytes to be signed
-
-    if (dy <= 0) {
-        src -= dy * rowBytes;
-        height += dy;
-    } else {
-        dst += dy * rowBytes;
-        height -= dy;
-        // now jump src/dst to the last scanline
-        src += (height - 1) * rowBytes;
-        dst += (height - 1) * rowBytes;
-        // now invert rowbytes so we copy backwards in the loop
-        rowBytes = -rowBytes;
-    }
-
-    if (dx <= 0) {
-        src -= dx << shift;
-        width += dx;
-    } else {
-        dst += dx << shift;
-        width -= dx;
-    }
-
-    // If the X-translation would push it completely beyond the region,
-    // then there's nothing to draw.
-    if (width <= 0) {
-        return true;
-    }
-
-    width <<= shift;    // now width is the number of bytes to move per line
-    while (--height >= 0) {
-        memmove(dst, src, width);
-        dst += rowBytes;
-        src += rowBytes;
-    }
-
-    this->notifyPixelsChanged();
-    return true;
-}