Revert of Remove deprecated paths from image filter infrastructure.

src/gpu/SkGpuDevice.h

Index: src/gpu/SkGpuDevice.h
diff --git a/src/gpu/SkGpuDevice.h b/src/gpu/SkGpuDevice.h
index 1923525070d92cc78ddb992787be8e25aec8872b..4eaeab7a721d75677d132a9666cf9243a45bd20b 100644
--- a/src/gpu/SkGpuDevice.h
+++ b/src/gpu/SkGpuDevice.h
@@ -130,6 +130,17 @@
     const SkBitmap& onAccessBitmap() override;
     bool onAccessPixels(SkPixmap*) override;
 
+    bool canHandleImageFilter(const SkImageFilter*) override;
+    virtual bool filterImage(const SkImageFilter*, const SkBitmap&,
+                             const SkImageFilter::Context&,
+                             SkBitmap*, SkIPoint*) override;
+
+    bool filterTexture(GrContext*, GrTexture*, int width, int height, const SkImageFilter*,
+                       const SkImageFilter::Context&,
+                       SkBitmap* result, SkIPoint* offset);
+
+    static SkImageFilter::Cache* NewImageFilterCache();
+
     // for debugging purposes only
     void drawTexture(GrTexture*, const SkRect& dst, const SkPaint&);