Add onImageInfo call to SkImage_Base.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1903483003

Review URL: https://codereview.chromium.org/1903483003
diff --git a/src/image/SkImage_Raster.cpp b/src/image/SkImage_Raster.cpp
index 892183a..a67128a 100644
--- a/src/image/SkImage_Raster.cpp
+++ b/src/image/SkImage_Raster.cpp
@@ -74,6 +74,10 @@
     SkImage_Raster(const SkImageInfo&, sk_sp<SkData>, size_t rb, SkColorTable*);
     virtual ~SkImage_Raster();
 
+    SkImageInfo onImageInfo() const override {
+        return fBitmap.info();
+    }
+
     bool onReadPixels(const SkImageInfo&, void*, size_t, int srcX, int srcY, CachingHint) const override;
     bool onPeekPixels(SkPixmap*) const override;
     SkData* onRefEncoded(GrContext*) const override;
@@ -178,7 +182,7 @@
 
     return GrRefCachedBitmapTexture(ctx, fBitmap, params);
 #endif
-    
+
     return nullptr;
 }