Remove SkImageFilter::getInputResult(), since its return value is not

src/effects/SkOffsetImageFilter.cpp

Index: src/effects/SkOffsetImageFilter.cpp
diff --git a/src/effects/SkOffsetImageFilter.cpp b/src/effects/SkOffsetImageFilter.cpp
index 2a4f71c0b2070d11629432d1ac88553d74649db4..ad5e49d776256b8e0c54deb17ca73ed9681dd056 100644
--- a/src/effects/SkOffsetImageFilter.cpp
+++ b/src/effects/SkOffsetImageFilter.cpp
@@ -14,7 +14,11 @@ bool SkOffsetImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& source,
                                         const SkMatrix& matrix,
                                         SkBitmap* result,
                                         SkIPoint* loc) {
-    SkBitmap src = this->getInputResult(0, proxy, source, matrix, loc);
+    SkBitmap src = source;
+    if (getInput(0) && !getInput(0)->filterImage(proxy, source, matrix, &src, loc)) {
+        return false;
+    }
+
     SkVector vec;
     matrix.mapVectors(&vec, &fOffset, 1);