Add texture compression utility

src/utils/SkTextureCompressor.h

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkTextureCompressor_DEFINED
+#define SkTextureCompressor_DEFINED
+
+class SkBitmap;
+class SkData;
+
+namespace SkTextureCompressor {
+    // Various texture compression formats that we support.
+    enum Format {
+        // Alpha only format.
+        kLATC_Format,
+
+        kLast_Format = kLATC_Format
+    };
+    static const int kFormatCnt = kLast_Format + 1;
+
+    // Returns an SKData holding a blob of compressed data that corresponds

[scroggo, 2014/06/09 20:54:18]

nit: SkData.

[krajcevski, 2014/06/09 21:06:02]

Done.

+    // to the bitmap. If the bitmap config cannot be compressed using the 

[scroggo, 2014/06/09 20:54:18]

SkBitmap::Config is deprecated. Use SkColorType.

[krajcevski, 2014/06/09 21:06:02]

Done.

+    // associated format, then we return NULL. The returned SkData will have
+    // a refcount of one.

[scroggo, 2014/06/09 20:54:18]

Typically I think we state that the caller is responsible for calling unref().

[krajcevski, 2014/06/09 21:06:02]

Done.

+    SkData *CompressBitmapToFormat(const SkBitmap &bitmap, Format format);

[scroggo, 2014/06/09 20:54:18]

nit: SkData* CompressBitmapToFormat
const SkBitmap& bitmap

[krajcevski, 2014/06/09 21:06:02]

Done.

+}
+
+#endif