Rename SkBitmapRegionDecoder and Create function

We no longer need to worry about namespace
conflicts SkBitmapRegionDecoder in Android (which
we are replacing).

Additionally, the static Create() function does not
need to repeat the name BitmapRegionDecoder.

BUG=skia:

Review URL: https://codereview.chromium.org/1415243007
diff --git a/dm/DMSrcSink.h b/dm/DMSrcSink.h
index a7cca83..78c6b5c 100644
--- a/dm/DMSrcSink.h
+++ b/dm/DMSrcSink.h
@@ -12,7 +12,7 @@
 #include "SkBBHFactory.h"
 #include "SkBBoxHierarchy.h"
 #include "SkBitmap.h"
-#include "SkBitmapRegionDecoderInterface.h"
+#include "SkBitmapRegionDecoder.h"
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkGPipe.h"
@@ -163,7 +163,7 @@
         kDivisor_Mode,
     };
 
-    BRDSrc(Path, SkBitmapRegionDecoderInterface::Strategy, Mode, CodecSrc::DstColorType, uint32_t);
+    BRDSrc(Path, SkBitmapRegionDecoder::Strategy, Mode, CodecSrc::DstColorType, uint32_t);
 
     Error draw(SkCanvas*) const override;
     SkISize size() const override;
@@ -171,7 +171,7 @@
     bool veto(SinkFlags) const override;
 private:
     Path                                     fPath;
-    SkBitmapRegionDecoderInterface::Strategy fStrategy;
+    SkBitmapRegionDecoder::Strategy          fStrategy;
     Mode                                     fMode;
     CodecSrc::DstColorType                   fDstColorType;
     uint32_t                                 fSampleSize;