remove/deprecate SkBitmap::getTexture, as it now always returns false

src/image/SkImage_Raster.cpp

Index: src/image/SkImage_Raster.cpp
diff --git a/src/image/SkImage_Raster.cpp b/src/image/SkImage_Raster.cpp
index 338c778ad95f08f56ca1535da82d81dbd1e6a66d..a8ef21d1da90a747b403a5a459030ac4450810bc 100644
--- a/src/image/SkImage_Raster.cpp
+++ b/src/image/SkImage_Raster.cpp
@@ -253,8 +253,6 @@ sk_sp<SkImage> SkMakeImageFromPixelRef(const SkImageInfo& info, SkPixelRef* pr,
 }
 
 sk_sp<SkImage> SkMakeImageFromRasterBitmap(const SkBitmap& bm, ForceCopyMode forceCopy) {
-    SkASSERT(nullptr == bm.getTexture());
-
     bool hasColorTable = false;
     if (kIndex_8_SkColorType == bm.colorType()) {
         SkAutoLockPixels autoLockPixels(bm);