Extend SkImageGenerator to support natively generated GrTextures

include/core/SkImageInfo.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImageInfo_DEFINED
 #define SkImageInfo_DEFINED
 
 #include "SkMath.h"
 #include "SkRect.h"
 #include "SkSize.h"
 
 class SkReadBuffer;
 class SkWriteBuffer;
 
 /**
+ *  This enum provides information about "how" an image will be used. For older GPUs that do not
+ *  support non-power-of-2 tiling, some routines need to know this information before they create
+ *  a texture.
+ */
+enum SkImageUsageType {
+    /* Image will not be tiled (regardless of filtering) */
+    kUntiled_SkImageUsageType,
+
+    /* Image will be tiled, but not filtered */
+    kTiled_Unfiltered_SkImageUsageType,
+
+    /* Image will be tiled and filtered */
+    kTiled_Filtered_SkImageUsageType,
+};
+
+/**
  *  Describes how to interpret the alpha compoent of a pixel.
  */
 enum SkAlphaType {
     kUnknown_SkAlphaType,
 
     /**
      *  All pixels are stored as opaque. This differs slightly from kIgnore in
      *  that kOpaque has correct "opaque" values stored in the pixels, while
      *  kIgnore may not, but in both cases the caller should treat the pixels
      *  as opaque.
@@ skipping 280 matching lines @@
     SkImageInfo(int width, int height, SkColorType ct, SkAlphaType at, SkColorProfileType pt)
         : fWidth(width)
         , fHeight(height)
         , fColorType(ct)
         , fAlphaType(at)
         , fProfileType(pt)
     {}
 };
 
 #endif