Switch to one-at-a-time SkPicture::clone interface

cc/resources/picture.cc

Index: cc/resources/picture.cc
diff --git a/cc/resources/picture.cc b/cc/resources/picture.cc
index a19fd33f3a0724906b5fad324c0bd7d3a5fc28ee..551d5d175e45b29e9e8193e75a49e1c0362e2037 100644
--- a/cc/resources/picture.cc
+++ b/cc/resources/picture.cc
@@ -231,15 +231,12 @@ void Picture::CloneForDrawing(int num_threads) {
   raster_thread_checker_.DetachFromThread();
 
   if (num_threads > 1) {
-    scoped_ptr<SkPicture[]> clones(new SkPicture[num_threads - 1]);
-    picture_->clone(&clones[0], num_threads - 1);
-
     for (int i = 0; i < num_threads - 1; i++) {
-      scoped_refptr<Picture> clone = make_scoped_refptr(
-          new Picture(skia::AdoptRef(new SkPicture(clones[i])),
-                      layer_rect_,
-                      opaque_rect_,
-                      pixel_refs_));
+      scoped_refptr<Picture> clone =
+          make_scoped_refptr(new Picture(skia::AdoptRef(picture_->clone()),

[danakj, 2014/07/11 15:30:40]

nit: FWIW make_scoped_refptr is redundant, that conversion happens implicitly.

[robertphillips, 2014/07/11 15:59:42]

Done.

+                                         layer_rect_,
+                                         opaque_rect_,
+                                         pixel_refs_));
       clones_.push_back(clone);
 
       clone->EmitTraceSnapshotAlias(this);