Revert of change all factories to return their base-class (patchset #1 id:1 of https://codereview.chromium.org/1535353002/ )

Reason for revert:
need to update some chrome/blink call-sites

Original issue's description:
> change all factories to return their base-class
>
> will watch DEPS roll to see if there are chrome sites needing updates
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1535353002
>
> TBR=
>
> Committed: https://skia.googlesource.com/skia/+/d63f60a36327e9580861205ebb35cade8c49bd34

TBR=
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1540203002

1 files changed, 1 insertions, 1 deletions

diff --git a/bench/MatrixConvolutionBench.cpp b/bench/MatrixConvolutionBench.cpp
index 05f0193cec..6302f1273b 100644
--- a/bench/MatrixConvolutionBench.cpp
+++ b/bench/MatrixConvolutionBench.cpp
@@ -50,7 +50,7 @@ protected:
 
 private:
     typedef Benchmark INHERITED;
-    SkImageFilter* fFilter;
+    SkMatrixConvolutionImageFilter* fFilter;
     SkString fName;
 };