cc: Give TilingData a Rect instead of a Size

cc/resources/picture_pile_base.cc

Index: cc/resources/picture_pile_base.cc
diff --git a/cc/resources/picture_pile_base.cc b/cc/resources/picture_pile_base.cc
index 2fb6ef5b84a282b1b90f36affe1c2eed68df6492..aa00876f7882f6d338f7b3f2751ceb2a79e14b5c 100644
--- a/cc/resources/picture_pile_base.cc
+++ b/cc/resources/picture_pile_base.cc
@@ -92,21 +92,29 @@ PicturePileBase::PicturePileBase(const PicturePileBase* other,
 PicturePileBase::~PicturePileBase() {
 }
 
-void PicturePileBase::Resize(const gfx::Size& new_size) {
-  if (size() == new_size)
+void PicturePileBase::SetTilingRect(const gfx::Rect& new_tiling_rect) {
+  if (tiling_rect() == new_tiling_rect)
     return;
 
-  gfx::Size old_size = size();
-  tiling_.SetTotalSize(new_size);
+  gfx::Rect old_tiling_rect = tiling_rect();
+  tiling_.SetTilingRect(new_tiling_rect);
 
   has_any_recordings_ = false;
 
-  // Find all tiles that contain any pixels outside the new size.
+  // Don't waste time in Resize figuring out what these hints should be.
+  recorded_viewport_ = gfx::Rect();
+
+  if (new_tiling_rect.origin() != old_tiling_rect.origin()) {
+    picture_map_.clear();
+    return;
+  }
+
+  // Find all tiles that contain any pixels outside the new rect.
   std::vector<PictureMapKey> to_erase;
   int min_toss_x = tiling_.FirstBorderTileXIndexFromSrcCoord(
-      std::min(old_size.width(), new_size.width()));
+      std::min(old_tiling_rect.right(), new_tiling_rect.right()));
   int min_toss_y = tiling_.FirstBorderTileYIndexFromSrcCoord(
-      std::min(old_size.height(), new_size.height()));
+      std::min(old_tiling_rect.bottom(), new_tiling_rect.bottom()));
   for (PictureMap::const_iterator it = picture_map_.begin();
        it != picture_map_.end();
        ++it) {
@@ -120,9 +128,6 @@ void PicturePileBase::Resize(const gfx::Size& new_size) {
 
   for (size_t i = 0; i < to_erase.size(); ++i)
     picture_map_.erase(to_erase[i]);
-
-  // Don't waste time in Resize figuring out what these hints should be.
-  recorded_viewport_ = gfx::Rect();
 }
 
 void PicturePileBase::SetMinContentsScale(float min_contents_scale) {
@@ -188,11 +193,11 @@ bool PicturePileBase::HasRecordingAt(int x, int y) {
 
 bool PicturePileBase::CanRaster(float contents_scale,
                                 const gfx::Rect& content_rect) {
-  if (tiling_.total_size().IsEmpty())
+  if (tiling_.tiling_rect().IsEmpty())
     return false;
   gfx::Rect layer_rect = gfx::ScaleToEnclosingRect(
       content_rect, 1.f / contents_scale);
-  layer_rect.Intersect(gfx::Rect(tiling_.total_size()));
+  layer_rect.Intersect(tiling_.tiling_rect());
 
   // Common case inside of viewport to avoid the slower map lookups.
   if (recorded_viewport_.Contains(layer_rect)) {
@@ -233,10 +238,10 @@ gfx::Rect PicturePileBase::PadRect(const gfx::Rect& rect) {
 
 scoped_ptr<base::Value> PicturePileBase::AsValue() const {
   scoped_ptr<base::ListValue> pictures(new base::ListValue());
-  gfx::Rect layer_rect(tiling_.total_size());
+  gfx::Rect tiling_rect(tiling_.tiling_rect());
   std::set<void*> appended_pictures;
   bool include_borders = true;
-  for (TilingData::Iterator tile_iter(&tiling_, layer_rect, include_borders);
+  for (TilingData::Iterator tile_iter(&tiling_, tiling_rect, include_borders);
        tile_iter;
        ++tile_iter) {
     PictureMap::const_iterator map_iter = picture_map_.find(tile_iter.index());