Make PicturePile pile.

This follows a similar policy as Android browser:

- If an invalidate only intersects the base plus at most one non-base SkPicture, then it creates a new SkPicture of that size.
- If an invalidate intersects two or more non-base SkPictures, then a new SkPicture is created at the top of the pile, sized to the union of the invalidate plus the bounds of all the intersecting pictures.
- Whenever new picture's area fully contains an existing picture, that old picture is destroyed.
- If an SkPicture's area would be >70% of the base, the pile is
  destroyed and the base SkPicture is recreated.

During the invalidate pass, invalidated pictures are represented as
Pictures with a size but no recording.  Then all the blank pictures
are filled in at the end of the Update().

BUG=163429

Review URL: https://chromiumcodereview.appspot.com/11299324

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@170917 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 7 insertions, 6 deletions

diff --git a/cc/picture_pile_impl.cc b/cc/picture_pile_impl.cc
index 2f89828..216643b 100644
--- a/cc/picture_pile_impl.cc
+++ b/cc/picture_pile_impl.cc
@@ -23,9 +23,9 @@ PicturePileImpl::~PicturePileImpl() {
 scoped_refptr<PicturePileImpl> PicturePileImpl::CloneForDrawing() const {
   TRACE_EVENT0("cc", "PicturePileImpl::CloneForDrawing");
   scoped_refptr<PicturePileImpl> clone = Create();
-  clone->pile_.resize(pile_.size());
-  for (size_t i = 0; i < pile_.size(); ++i)
-    clone->pile_[i] = pile_[i]->Clone();
+  for (PicturePile::Pile::const_iterator i = pile_.begin();
+       i != pile_.end(); ++i)
+    clone->pile_.push_back((*i)->Clone());
 
   return clone;
 }
@@ -40,10 +40,11 @@ void PicturePileImpl::Raster(SkCanvas* canvas, gfx::Rect rect,
   SkRect layer_skrect = SkRect::MakeXYWH(rect.x(), rect.y(),
                                          rect.width(), rect.height());
   canvas->clipRect(layer_skrect);
-  for (size_t i = 0; i < pile_.size(); ++i) {
-    if (!pile_[i]->LayerRect().Intersects(rect))
+  for (PicturePile::Pile::const_iterator i = pile_.begin();
+       i != pile_.end(); ++i) {
+    if (!(*i)->LayerRect().Intersects(rect))
       continue;
-    pile_[i]->Raster(canvas);
+    (*i)->Raster(canvas);
 
     SkISize deviceSize = canvas->getDeviceSize();
     stats->totalPixelsRasterized += deviceSize.width() * deviceSize.height();