Various MSAN fixes

Initialize fBitmap.* in SkPictureData

Change-Id: I72c91a3a85881ae0ca7f64702263e2f8ea02a5c8
Reviewed-on: https://skia-review.googlesource.com/98740
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>

src/core/SkPictureData.cpp

@@ -117,6 +117,8 @@ void SkPictureData::init() {
     fVerticesCount = 0;
     fImageRefs = nullptr;
     fImageCount = 0;
+    fBitmapImageCount = 0;
+    fBitmapImageRefs = nullptr;
     fFactoryPlayback = nullptr;
 }