Add animating blur image filter GM/slide/bench

Probably still worth having but I haven't been able to reproduce the perf regression in 
crbug.com/668179 with it yet.

Change-Id: If3b0f2998ff38a17a173895ed9cea6950a81f6b7
Reviewed-on: https://skia-review.googlesource.com/5382
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>

gm/animatedimageblurs.cpp

@@ -0,0 +1,139 @@
+/*
+ * 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 "gm.h"
+#include "SkAnimTimer.h"
+#include "SkBlurImageFilter.h"
+#include "SkRandom.h"
+#include "SkRRect.h"
+
+static const SkScalar kBlurMax = 7.0f;
+static const int kNumNodes = 30;
+static const int kWidth = 512;
+static const int kHeight = 512;
+static const SkScalar kBlurAnimationDuration = 4.0f; // in secs
+
+// This GM draws a lot of layers with animating BlurImageFilters
+class AnimatedImageBlurs : public skiagm::GM {
+public:
+    AnimatedImageBlurs() : fLastTime(0.0f) {
+        this->setBGColor(sk_tool_utils::color_to_565(0xFFCCCCCC));
+    }
+
+protected:
+    bool runAsBench() const override { return true; }
+
+    SkString onShortName() override { return SkString("animated-image-blurs"); }
+
+    SkISize onISize() override { return SkISize::Make(kWidth, kHeight); }
+
+    void onOnceBeforeDraw() override {
+        for (int i = 0; i < kNumNodes; ++i) {
+            fNodes[i].init(&fRand);
+        }
+    }
+
+    void onDraw(SkCanvas* canvas) override {
+        SkPaint paint;
+        paint.setAntiAlias(true);
+
+        for (int i = 0; i < kNumNodes; ++i) {
+            SkPaint layerPaint;
+            layerPaint.setImageFilter(SkBlurImageFilter::Make(fNodes[i].sigma(),
+                                                              fNodes[i].sigma(),
+                                                              nullptr));
+
+            canvas->saveLayer(nullptr, &layerPaint);
+                // The rect is outset to block the circle case
+                SkRect rect = SkRect::MakeLTRB(fNodes[i].pos().fX - fNodes[i].size()-0.5f,
+                                               fNodes[i].pos().fY - fNodes[i].size()-0.5f,
+                                               fNodes[i].pos().fX + fNodes[i].size()+0.5f,
+                                               fNodes[i].pos().fY + fNodes[i].size()+0.5f);
+                SkRRect rrect = SkRRect::MakeRectXY(rect, fNodes[i].size(), fNodes[i].size());
+                canvas->drawRRect(rrect, paint);
+            canvas->restore();
+        }
+    }
+
+    bool onAnimate(const SkAnimTimer& timer) override {
+        if (0.0f != fLastTime) {
+            for (int i = 0; i < kNumNodes; ++i) {
+                fNodes[i].update(timer, fLastTime);
+            }
+        }
+
+        fLastTime = timer.secs();
+        return true;
+    }
+
+private:
+    class Node {
+    public:
+        Node()
+            : fSize(0.0f)
+            , fPos { 0.0f, 0.0f }
+            , fDir { 1.0f, 0.0f }
+            , fBlurOffset(0.0f)
+            , fBlur(fBlurOffset)
+            , fSpeed(0.0f) {
+        }
+
+        void init(SkRandom* rand) {
+            fSize = rand->nextRangeF(10.0f, 60.f);
+            fPos.fX = rand->nextRangeF(fSize, kWidth - fSize);
+            fPos.fY = rand->nextRangeF(fSize, kHeight - fSize);
+            fDir.fX = rand->nextRangeF(-1.0f, 1.0f);
+            fDir.fY = SkScalarSqrt(1.0f - fDir.fX * fDir.fX);
+            if (rand->nextBool()) {
+                fDir.fY = -fDir.fY;
+            }
+            fBlurOffset = rand->nextRangeF(0.0f, kBlurMax);
+            fBlur = fBlurOffset;
+            fSpeed = rand->nextRangeF(20.0f, 60.0f);
+        }
+
+        void update(const SkAnimTimer& timer, SkScalar lastTime) {
+
+            SkScalar deltaTime = timer.secs() - lastTime;
+
+            fPos.fX += deltaTime * fSpeed * fDir.fX;
+            fPos.fY += deltaTime * fSpeed * fDir.fY;
+            if (fPos.fX >= kWidth || fPos.fX < 0.0f) {
+                fPos.fX = SkTPin<SkScalar>(fPos.fX, 0.0f, kWidth);
+                fDir.fX = -fDir.fX;
+            }
+            if (fPos.fY >= kHeight || fPos.fY < 0.0f) {
+                fPos.fY = SkTPin<SkScalar>(fPos.fY, 0.0f, kHeight);
+                fDir.fY = -fDir.fY;
+            }
+
+            fBlur = timer.pingPong(kBlurAnimationDuration, fBlurOffset, 0.0f, kBlurMax);
+        }
+
+        SkScalar sigma() const { return fBlur; }
+        const SkPoint& pos() const { return fPos; }
+        SkScalar size() const { return fSize; }
+
+    private:
+        SkScalar fSize;
+        SkPoint  fPos;
+        SkVector fDir;
+        SkScalar fBlurOffset;
+        SkScalar fBlur;
+        SkScalar fSpeed;
+    };
+
+    Node     fNodes[kNumNodes];
+    SkRandom fRand;
+    SkScalar fLastTime;
+
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM(return new AnimatedImageBlurs;)

gn/gm.gni

@@ -15,6 +15,7 @@ gm_sources = [
   "$_gm/all_bitmap_configs.cpp",
   "$_gm/alphagradients.cpp",
   "$_gm/animatedGif.cpp",
+  "$_gm/animatedimageblurs.cpp",
   "$_gm/anisotropic.cpp",
   "$_gm/annotated_text.cpp",
   "$_gm/arcofzorro.cpp",