Revert "remove toString"

This reverts commit 5191880cbf3ee4d122b0d11b4945fbab0784fda7.

Reason for revert: broke flutter

Original change's description:
> remove toString
> 
> toString may have been used by obsolete debugger only
> find out if that is so
> 
> R=​brianosman@google.com,bsalomon@google.com
> 
> Docs-Preview: https://skia.org/?cl=119894
> Bug:830651
> Change-Id: I737f19b7d3fbc869bea2f443fa3b5ed7c1393ffd
> Reviewed-on: https://skia-review.googlesource.com/119894
> Commit-Queue: Cary Clark <caryclark@google.com>
> Reviewed-by: Brian Salomon <bsalomon@google.com>

TBR=bsalomon@google.com,brianosman@google.com,caryclark@google.com,caryclark@skia.org

Change-Id: I9f81de6c3615ee0608bcea9081b77239b4b8816c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 830651
Reviewed-on: https://skia-review.googlesource.com/129340
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Cary Clark <caryclark@google.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/tests/ImageFilterTest.cpp b/tests/ImageFilterTest.cpp
index b57af7f30b..8e46715fbb 100644
--- a/tests/ImageFilterTest.cpp
+++ b/tests/ImageFilterTest.cpp
@@ -59,6 +59,7 @@ public:
         return sk_sp<SkImageFilter>(new MatrixTestImageFilter(reporter, expectedMatrix));
     }
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(MatrixTestImageFilter)
 
 protected:
@@ -102,6 +103,7 @@ public:
         return nullptr;
     }
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(FailImageFilter)
 
 private:
@@ -113,6 +115,11 @@ sk_sp<SkFlattenable> FailImageFilter::CreateProc(SkReadBuffer& buffer) {
     return sk_sp<SkFlattenable>(new FailImageFilter());
 }
 
+void FailImageFilter::toString(SkString* str) const {
+    str->appendf("FailImageFilter: (");
+    str->append(")");
+}
+
 void draw_gradient_circle(SkCanvas* canvas, int width, int height) {
     SkScalar x = SkIntToScalar(width / 2);
     SkScalar y = SkIntToScalar(height / 2);
@@ -290,6 +297,7 @@ public:
             : SkImageFilter(nullptr, 0, nullptr), fBounds(bounds) {}
 
 private:
+    void toString(SkString*) const override {}
     Factory getFactory() const override { return nullptr; }
 
     sk_sp<SkSpecialImage> onFilterImage(SkSpecialImage* src, const Context&,
@@ -312,6 +320,11 @@ sk_sp<SkFlattenable> MatrixTestImageFilter::CreateProc(SkReadBuffer& buffer) {
     return nullptr;
 }
 
+void MatrixTestImageFilter::toString(SkString* str) const {
+    str->appendf("MatrixTestImageFilter: (");
+    str->append(")");
+}
+
 static sk_sp<SkImage> make_small_image() {
     auto surface(SkSurface::MakeRasterN32Premul(kBitmapSize, kBitmapSize));
     SkCanvas* canvas = surface->getCanvas();
@@ -1863,6 +1876,8 @@ DEF_TEST(ImageFilterColorSpaceDAG, reporter) {
     public:
         TestFilter() : INHERITED(nullptr, 0, nullptr) {}
 
+        void toString(SkString*) const override {}
+
         Factory getFactory() const override { return nullptr; }
 
         size_t cloneCount() const { return fCloneCount; }