Move SkBitmapRegionDecoder to include/android and src/android

tools/android/SkBitmapRegionDecoderPriv.h

-/*
- * Copyright 2015 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkBitmapRegionDecoderPriv_DEFINED
-#define SkBitmapRegionDecoderPriv_DEFINED
-
-inline float get_scale_from_sample_size(uint32_t sampleSize) {
-    return 1.0f / (float) sampleSize;
-}
-
-enum SubsetType {
-    kFullyInside_SubsetType,
-    kPartiallyInside_SubsetType,
-    kOutside_SubsetType,
-};
-
-/*
- * Corrects image subset offsets and dimensions in order to perform a valid decode.
- * Also indicates if the image subset should be placed at an offset within the
- * output bitmap.
- *
- * Values of output variables are undefined if the SubsetType is kInvalid.
- *
- * @param imageDims Original image dimensions.
- * @param subset    As input, the subset that the client requested.
- *                  As output, the image subset that we will decode.
- * @param outX      The left offset of the image subset within the output bitmap.
- * @param outY      The top offset of the image subset within the output bitmap.
- *
- * @return An indication of how the subset is contained in the image.
- *         If the return value is kInvalid, values of output variables are undefined.
- */
-inline SubsetType adjust_subset_rect(const SkISize& imageDims, SkIRect* subset, int* outX,
-        int* outY) {
-    // These must be at least zero, we can't start decoding the image at a negative coordinate.
-    int left = SkTMax(0, subset->fLeft);
-    int top = SkTMax(0, subset->fTop);
-
-    // If input offsets are less than zero, we decode to an offset location in the output bitmap.
-    *outX = left - subset->fLeft;
-    *outY = top - subset->fTop;
-
-    // Make sure we don't decode pixels past the edge of the image or past the edge of the subset.
-    int width = SkTMin(imageDims.width() - left, subset->width() - *outX);
-    int height = SkTMin(imageDims.height() - top, subset->height() - *outY);
-    if (width <= 0 || height <= 0) {
-        return SubsetType::kOutside_SubsetType;
-    }
-
-    subset->setXYWH(left, top, width, height);
-    if ((*outX != 0) || (*outY != 0) || (width != subset->width()) ||
-            (height != subset->height())) {
-        return SubsetType::kPartiallyInside_SubsetType;
-    }
-
-    return SubsetType::kFullyInside_SubsetType;
-}
-
-#endif // SkBitmapRegionDecoderPriv_DEFINED