Fix imagemagnifier GM quality and speed.

The imagemagnifier GM was applying the filter both to a saveLayer()
restore() around the whole scene, as well as to each individual
text draw.

Applying the filter only in the saveLayer() makes it run ~20x faster
on my Linux box, and the quality is improved as well (since the
primitives are not double-filtered).

BUG=skia:

Review URL: https://codereview.chromium.org/637283009

1 files changed, 6 insertions, 5 deletions

diff --git a/gm/imagemagnifier.cpp b/gm/imagemagnifier.cpp
index e2847b4c67..371b3088f9 100644
--- a/gm/imagemagnifier.cpp
+++ b/gm/imagemagnifier.cpp
@@ -35,23 +35,24 @@ protected:
     }
 
     virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
-        SkPaint paint;
-        paint.setImageFilter(
+        SkPaint filterPaint;
+        filterPaint.setImageFilter(
             SkMagnifierImageFilter::Create(
                 SkRect::MakeXYWH(SkIntToScalar(100), SkIntToScalar(100),
                                  SkIntToScalar(WIDTH / 2),
                                  SkIntToScalar(HEIGHT / 2)),
                 100))->unref();
-        canvas->saveLayer(NULL, &paint);
-        paint.setAntiAlias(true);
-        sk_tool_utils::set_portable_typeface(&paint);
+        canvas->saveLayer(NULL, &filterPaint);
         const char* str = "The quick brown fox jumped over the lazy dog.";
         SkRandom rand;
         for (int i = 0; i < 25; ++i) {
             int x = rand.nextULessThan(WIDTH);
             int y = rand.nextULessThan(HEIGHT);
+            SkPaint paint;
+            sk_tool_utils::set_portable_typeface(&paint);
             paint.setColor(rand.nextBits(24) | 0xFF000000);
             paint.setTextSize(rand.nextRangeScalar(0, 300));
+            paint.setAntiAlias(true);
             canvas->drawText(str, strlen(str), SkIntToScalar(x),
                              SkIntToScalar(y), paint);
         }