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/bench/nanobench.cpp b/bench/nanobench.cpp
index 2e566da..264e4a1 100644
--- a/bench/nanobench.cpp
+++ b/bench/nanobench.cpp
@@ -26,7 +26,7 @@
 #include "SubsetZoomBench.h"
 #include "Stats.h"
 
-#include "SkBitmapRegionDecoderInterface.h"
+#include "SkBitmapRegionDecoder.h"
 #include "SkBBoxHierarchy.h"
 #include "SkCanvas.h"
 #include "SkCodec.h"
@@ -588,11 +588,11 @@
     return true;
 }
 
-static bool valid_brd_bench(SkData* encoded, SkBitmapRegionDecoderInterface::Strategy strategy,
+static bool valid_brd_bench(SkData* encoded, SkBitmapRegionDecoder::Strategy strategy,
         SkColorType colorType, uint32_t sampleSize, uint32_t minOutputSize, int* width,
         int* height) {
-    SkAutoTDelete<SkBitmapRegionDecoderInterface> brd(
-            SkBitmapRegionDecoderInterface::CreateBitmapRegionDecoder(encoded, strategy));
+    SkAutoTDelete<SkBitmapRegionDecoder> brd(
+            SkBitmapRegionDecoder::Create(encoded, strategy));
     if (nullptr == brd.get()) {
         // This is indicates that subset decoding is not supported for a particular image format.
         return false;
@@ -956,12 +956,12 @@
         // Run the BRDBenches
         // We will benchmark multiple BRD strategies.
         static const struct {
-            SkBitmapRegionDecoderInterface::Strategy    fStrategy;
+            SkBitmapRegionDecoder::Strategy    fStrategy;
             const char*                                 fName;
         } strategies[] = {
-            { SkBitmapRegionDecoderInterface::kOriginal_Strategy,    "BRD" },
-            { SkBitmapRegionDecoderInterface::kCanvas_Strategy,      "BRD_canvas" },
-            { SkBitmapRegionDecoderInterface::kAndroidCodec_Strategy, "BRD_android_codec" },
+            { SkBitmapRegionDecoder::kOriginal_Strategy,    "BRD" },
+            { SkBitmapRegionDecoder::kCanvas_Strategy,      "BRD_canvas" },
+            { SkBitmapRegionDecoder::kAndroidCodec_Strategy, "BRD_android_codec" },
         };
 
         // We intend to create benchmarks that model the use cases in
@@ -986,10 +986,10 @@
                 fBenchType = strategies[fCurrentBRDStrategy].fName;
 
                 const SkString& path = fImages[fCurrentBRDImage];
-                const SkBitmapRegionDecoderInterface::Strategy strategy =
+                const SkBitmapRegionDecoder::Strategy strategy =
                         strategies[fCurrentBRDStrategy].fStrategy;
 
-                if (SkBitmapRegionDecoderInterface::kOriginal_Strategy == strategy) {
+                if (SkBitmapRegionDecoder::kOriginal_Strategy == strategy) {
                     // Disable png and jpeg for SkImageDecoder:
                     if (!FLAGS_jpgBuildTileIndex) {
                         if (path.endsWith("JPEG") || path.endsWith("JPG") ||