Revert "Delete SkGaussianEdgeShader"

This reverts commit 64790a3714467300848971aa153aca8cea91cf7b.

Reason for revert: pending Android fix merge.

Original change's description:
> Delete SkGaussianEdgeShader
> 
> No longer used.
> 
> Change-Id: I65a61696060ca19f528066ea587e140798450e36
> Reviewed-on: https://skia-review.googlesource.com/18132
> Reviewed-by: Jim Van Verth <jvanverth@google.com>
> Commit-Queue: Florin Malita <fmalita@chromium.org>
> 

TBR=jvanverth@google.com,fmalita@chromium.org,reed@google.com
No-Presubmit: true
No-Tree-Checks: true
No-Try: true

Change-Id: I88a428e942c78b1fc8e70501ba7fdda5727b2ab2
Reviewed-on: https://skia-review.googlesource.com/18156
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>

2 files changed, 122 insertions, 0 deletions

diff --git a/src/effects/SkGaussianEdgeShader.cpp b/src/effects/SkGaussianEdgeShader.cpp
new file mode 100644
index 0000000000..c710b949d3
--- /dev/null
+++ b/src/effects/SkGaussianEdgeShader.cpp
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkGaussianEdgeShader.h"
+#include "SkReadBuffer.h"
+#include "SkWriteBuffer.h"
+
+class SkArenaAlloc;
+
+ /** \class SkGaussianEdgeShaderImpl
+ This subclass of shader applies a Gaussian to shadow edge
+
+ If the primitive supports an implicit distance to the edge, the radius of the blur is specified
+ by r & g values of the color in 14.2 fixed point. For spot shadows, we increase the stroke width
+ to set the shadow against the shape. This pad is specified by b, also in 6.2 fixed point.
+
+ When not using implicit distance, then b in the input color represents the input to the
+ blur function.
+ */
+class SkGaussianEdgeShaderImpl : public SkShaderBase {
+public:
+    SkGaussianEdgeShaderImpl() {}
+
+    bool isOpaque() const override;
+
+#if SK_SUPPORT_GPU
+    sk_sp<GrFragmentProcessor> asFragmentProcessor(const AsFPArgs&) const override;
+#endif
+
+    SK_TO_STRING_OVERRIDE()
+    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkGaussianEdgeShaderImpl)
+
+protected:
+    void flatten(SkWriteBuffer&) const override;
+    Context* onMakeContext(const ContextRec& rec, SkArenaAlloc* storage) const override {
+        return nullptr;
+    }
+private:
+    friend class SkGaussianEdgeShader;
+
+    typedef SkShaderBase INHERITED;
+};
+
+////////////////////////////////////////////////////////////////////////////
+
+#if SK_SUPPORT_GPU
+
+#include "effects/GrBlurredEdgeFragmentProcessor.h"
+
+////////////////////////////////////////////////////////////////////////////
+
+sk_sp<GrFragmentProcessor> SkGaussianEdgeShaderImpl::asFragmentProcessor(const AsFPArgs&) const {
+    return GrBlurredEdgeFP::Make(GrBlurredEdgeFP::kGaussian_Mode);
+}
+
+#endif
+
+////////////////////////////////////////////////////////////////////////////
+
+bool SkGaussianEdgeShaderImpl::isOpaque() const {
+    return false;
+}
+
+////////////////////////////////////////////////////////////////////////////
+
+#ifndef SK_IGNORE_TO_STRING
+void SkGaussianEdgeShaderImpl::toString(SkString* str) const {
+    str->appendf("GaussianEdgeShader: ()");
+}
+#endif
+
+sk_sp<SkFlattenable> SkGaussianEdgeShaderImpl::CreateProc(SkReadBuffer& buf) {
+    return sk_make_sp<SkGaussianEdgeShaderImpl>();
+}
+
+void SkGaussianEdgeShaderImpl::flatten(SkWriteBuffer& buf) const {
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+sk_sp<SkShader> SkGaussianEdgeShader::Make() {
+    return sk_make_sp<SkGaussianEdgeShaderImpl>();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkGaussianEdgeShader)
+SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkGaussianEdgeShaderImpl)
+SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END
+
+///////////////////////////////////////////////////////////////////////////////
diff --git a/src/effects/SkGaussianEdgeShader.h b/src/effects/SkGaussianEdgeShader.h
new file mode 100644
index 0000000000..f0554dd0a7
--- /dev/null
+++ b/src/effects/SkGaussianEdgeShader.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkGaussianEdgeShader_DEFINED
+#define SkGaussianEdgeShader_DEFINED
+
+#include "SkShaderBase.h"
+
+class SK_API SkGaussianEdgeShader {
+public:
+    /** Returns a shader that applies a Gaussian blur depending on distance to the edge
+    * Currently this is only useable with Circle and RRect shapes on the GPU backend.
+    * Raster will draw nothing.
+    */
+    static sk_sp<SkShader> Make();
+
+    SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
+
+private:
+    SkGaussianEdgeShader(); // can't be instantiated
+};
+
+#endif