Change call-sites now that SkCanvas is not ref-counted

cc/trees/layer_tree_host_pixeltest_masks.cc

Index: cc/trees/layer_tree_host_pixeltest_masks.cc
diff --git a/cc/trees/layer_tree_host_pixeltest_masks.cc b/cc/trees/layer_tree_host_pixeltest_masks.cc
index 87e92a43553e64c984710db6af7aafb7eaaaf373..0ce262cb50a7f6f38df6945936c4ea50e9008d3f 100644
--- a/cc/trees/layer_tree_host_pixeltest_masks.cc
+++ b/cc/trees/layer_tree_host_pixeltest_masks.cc
@@ -40,8 +40,8 @@ class MaskContentLayerClient : public ContentLayerClient {
   scoped_refptr<DisplayItemList> PaintContentsToDisplayList(
       PaintingControlSetting picture_control) override {
     SkPictureRecorder recorder;
-    sk_sp<SkCanvas> canvas = sk_ref_sp(
-        recorder.beginRecording(gfx::RectToSkRect(gfx::Rect(bounds_))));
+    SkCanvas* canvas =
+        recorder.beginRecording(gfx::RectToSkRect(gfx::Rect(bounds_)));
 
     SkPaint paint;
     paint.setStyle(SkPaint::kStroke_Style);
@@ -163,8 +163,8 @@ class CheckerContentLayerClient : public ContentLayerClient {
   scoped_refptr<DisplayItemList> PaintContentsToDisplayList(
       PaintingControlSetting picture_control) override {
     SkPictureRecorder recorder;
-    sk_sp<SkCanvas> canvas = sk_ref_sp(
-        recorder.beginRecording(gfx::RectToSkRect(gfx::Rect(bounds_))));
+    SkCanvas* canvas =
+        recorder.beginRecording(gfx::RectToSkRect(gfx::Rect(bounds_)));
 
     SkPaint paint;
     paint.setStyle(SkPaint::kStroke_Style);
@@ -207,8 +207,8 @@ class CircleContentLayerClient : public ContentLayerClient {
   scoped_refptr<DisplayItemList> PaintContentsToDisplayList(
       PaintingControlSetting picture_control) override {
     SkPictureRecorder recorder;
-    sk_sp<SkCanvas> canvas = sk_ref_sp(
-        recorder.beginRecording(gfx::RectToSkRect(gfx::Rect(bounds_))));
+    SkCanvas* canvas =
+        recorder.beginRecording(gfx::RectToSkRect(gfx::Rect(bounds_)));
 
     SkPaint paint;
     paint.setStyle(SkPaint::kFill_Style);