Makes tile-creation lazy

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 962d927599354b7a70ae7ae7e4ab462112416d31..89bb7deb9b22fc05f62f5ba8ee2eb95211d37181 100644
--- a/cc/layers/picture_layer_impl_unittest.cc
+++ b/cc/layers/picture_layer_impl_unittest.cc
@@ -32,14 +32,6 @@ class TestablePictureLayerImpl : public PictureLayerImpl {
   PictureLayerTilingSet& tilings() { return *tilings_; }
   Region& invalidation() { return invalidation_; }
 
-  virtual gfx::Size CalculateTileSize(
-      gfx::Size current_tile_size,
-      gfx::Size content_bounds) OVERRIDE {
-    if (current_tile_size.IsEmpty())
-      return gfx::Size(100, 100);
-    return current_tile_size;
-  }
-
   using PictureLayerImpl::AddTiling;
   using PictureLayerImpl::CleanUpTilingsOnActiveLayer;
 
@@ -169,8 +161,12 @@ class PictureLayerImplTest : public testing::Test {
     active_layer_->AddTiling(2.3f);
     active_layer_->AddTiling(1.0f);
     active_layer_->AddTiling(0.5f);
+    for (size_t i = 0; i < active_layer_->tilings().num_tilings(); ++i)
+      active_layer_->tilings().tiling_at(i)->AllTilesForTesting();
     pending_layer_->invalidation() = invalidation;
     pending_layer_->SyncFromActiveLayer();
+    for (size_t i = 0; i < pending_layer_->tilings().num_tilings(); ++i)
+      pending_layer_->tilings().tiling_at(i)->AllTilesForTesting();
   }
 
   void SetupPendingTree(
@@ -402,7 +398,9 @@ TEST_F(PictureLayerImplTest, NoInvalidationBoundsChange) {
       EXPECT_TRUE(*iter);
       EXPECT_FALSE(iter.geometry_rect().IsEmpty());
       if (iter.geometry_rect().right() >= active_content_bounds.width() ||
-          iter.geometry_rect().bottom() >= active_content_bounds.height()) {
+          iter.geometry_rect().bottom() >= active_content_bounds.height() ||
+          tiling->tile_bounds() !=
+              active_layer_->tilings().tiling_at(i)->tile_bounds()) {
         EXPECT_EQ(pending_pile, iter->picture_pile());
       } else {
         EXPECT_EQ(active_pile, iter->picture_pile());