Added a few bench for some image filters

bench/MagnifierBench.cpp

Index: bench/MagnifierBench.cpp
===================================================================
--- bench/MagnifierBench.cpp	(revision 0)
+++ bench/MagnifierBench.cpp	(revision 0)
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "SkBenchmark.h"
+#include "SkCanvas.h"
+#include "SkMagnifierImageFilter.h"
+
+#define WIDTH 500
+#define HEIGHT 500
+
+class MagnifierBench : public SkBenchmark {
+public:
+    MagnifierBench(void* param) : INHERITED(param) {
+    }
+
+protected:
+    virtual const char* onGetName() SK_OVERRIDE {
+        return "magnifier";
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        SkPaint paint;
+        paint.setImageFilter(
+            new SkMagnifierImageFilter(
+                SkRect::MakeXYWH(SkIntToScalar(125), SkIntToScalar(125),
+                                 SkIntToScalar(WIDTH / 2),
+                                 SkIntToScalar(HEIGHT / 2)), 100))->unref();
+        canvas->saveLayer(NULL, &paint);
+        paint.setAntiAlias(true);
+        const char* str = "The quick brown fox jumped over the lazy dog.";

[Stephen White, 2013/04/15 15:34:21]

We should probably rewrite this one (as well as the GM) to draw a smaller image.

[sugoi1, 2013/04/19 18:09:42]

Done. I made it twice as small in each direction, so 4 times smaller, but I
haven't changed the GM.

+        srand(1234);
+        for (int i = 0; i < 25; ++i) {
+            int x = rand() % WIDTH;
+            int y = rand() % HEIGHT;
+            paint.setColor(rand() % 0x1000000 | 0xFF000000);
+            paint.setTextSize(SkIntToScalar(rand() % 300));
+            canvas->drawText(str, strlen(str), SkIntToScalar(x),
+                             SkIntToScalar(y), paint);
+        }
+        canvas->restore();
+    }
+
+private:
+    typedef SkBenchmark INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+DEF_BENCH( return new MagnifierBench(p); )
+