cc: Pass ideal contents scale to PictureLayerTiling UpdateTilePriorities.

cc/layers/picture_layer_impl_unittest.cc

Index: cc/layers/picture_layer_impl_unittest.cc
diff --git a/cc/layers/picture_layer_impl_unittest.cc b/cc/layers/picture_layer_impl_unittest.cc
index bb61f4e4deae11b9a0dcdd9f649f0082bfe4608a..45180f3a61d72cd442126578020bd9cc5886ee71 100644
--- a/cc/layers/picture_layer_impl_unittest.cc
+++ b/cc/layers/picture_layer_impl_unittest.cc
@@ -1984,13 +1984,18 @@ TEST_F(PictureLayerImplTest, LayerEvictionTileIterator) {
   std::set<Tile*> all_tiles_set(all_tiles.begin(), all_tiles.end());
 
   bool mark_required = false;
-  for (std::vector<Tile*>::iterator it = all_tiles.begin();
-       it != all_tiles.end();
-       ++it) {
-    Tile* tile = *it;
-    if (mark_required)
-      tile->MarkRequiredForActivation();
-    mark_required = !mark_required;
+  for (size_t i = 0; i < tilings.size(); ++i) {
+    PictureLayerTiling* tiling = tilings.at(i);
+    for (PictureLayerTiling::CoverageIterator iter(
+             tiling,
+             pending_layer_->contents_scale_x(),
+             pending_layer_->visible_content_rect());
+         iter;
+         ++iter) {
+      if (mark_required)
+        iter->MarkRequiredForActivation();
+      mark_required = !mark_required;
+    }

[sohanjg, 2014/06/20 13:35:20]

I think we shouldnt be iterating over all the tiles, instead only in the visible
content rect for activating tiles here, hence the CoverageIterator. 

[enne (OOO), 2014/06/25 18:33:07]

I think that's an ok change.  This is just a test, so...

Can you count how many things are marked and how many things are not marked and
DCHECK that there's at least one thing in each category? (i.e. test that the
test is testing something?)

[vmpstr, 2014/06/25 21:08:52]

I agree with this change. I was considering making that myself, since required
tiles might be handled differently later on, and I would prefer to have an
assurance that those tiles would only be in the visible rect.

[sohanjg, 2014/06/26 08:30:51]

Done.

   }
 
   // Sanity checks.
@@ -2064,7 +2069,6 @@ TEST_F(PictureLayerImplTest, LayerEvictionTileIterator) {
   }
 
   EXPECT_TRUE(reached_visible);
-  EXPECT_TRUE(reached_required);

[sohanjg, 2014/06/20 13:35:20]

As mentioned above, this check is not required.

[enne (OOO), 2014/06/25 18:33:07]

This still seems valid to me.  I don't understand.

   EXPECT_EQ(65u, unique_tiles.size());
 
   scale_index = 0;