Some improvements to LATC compression

R=bsalomon@google.com

Author: krajcevski@google.com

Review URL: https://codereview.chromium.org/347673002
diff --git a/src/utils/SkTextureCompressor.h b/src/utils/SkTextureCompressor.h
index 38fb5ea..7dda66b 100644
--- a/src/utils/SkTextureCompressor.h
+++ b/src/utils/SkTextureCompressor.h
@@ -8,6 +8,8 @@
 #ifndef SkTextureCompressor_DEFINED
 #define SkTextureCompressor_DEFINED
 
+#include "SkImageInfo.h"
+
 class SkBitmap;
 class SkData;
 
@@ -26,6 +28,12 @@
     // associated format, then we return NULL. The caller is responsible for
     // calling unref() on the returned data.
     SkData* CompressBitmapToFormat(const SkBitmap& bitmap, Format format);
+
+    // Compresses the given src data into dst. The src data is assumed to be
+    // large enough to hold width*height pixels. The dst data is expected to
+    // be large enough to hold the compressed data according to the format.
+    bool CompressBufferToFormat(uint8_t* dst, const uint8_t* src, SkColorType srcColorType,
+                                int width, int height, int rowBytes, Format format);
 }
 
 #endif