cc: Fix CHECK failure in PictureLayerImpl::UpdateTilePriorities

The should_update_tile_priorities_ in UpdateTilePriorities my fail and
here's the sequence of events:

* Context loss while layer is invisible, which clears
should_update_tile_priorities_
* CalculateContentsScale is skipped because layer is invisible
* Layer becomes visible in next commit, and active layer SyncTiling
during the commit will fail the check.

Any condition that causes CalculateContentsScale on the layer works as
well.

Internal bug b/11265055

BUG=
TEST=PictureLayerImplTest.SyncTilingAfterReleaseResource

Review URL: https://codereview.chromium.org/38863002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230735 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 17 insertions, 1 deletions

diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 36b2ba9..0ab4a5d 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -611,7 +611,8 @@ void PictureLayerImpl::SyncTiling(
   // get updated prior to drawing or activation.  If this tree does not
   // need update draw properties, then its transforms are up to date and
   // we can create tiles for this tiling immediately.
-  if (!layer_tree_impl()->needs_update_draw_properties())
+  if (!layer_tree_impl()->needs_update_draw_properties() &&
+      should_update_tile_priorities_)
     UpdateTilePriorities();
 }
 
diff --git a/cc/layers/picture_layer_impl_unittest.cc b/cc/layers/picture_layer_impl_unittest.cc
index f9dfb99..2f72c7d 100644
--- a/cc/layers/picture_layer_impl_unittest.cc
+++ b/cc/layers/picture_layer_impl_unittest.cc
@@ -1106,6 +1106,21 @@ TEST_F(PictureLayerImplTest, ActivateUninitializedLayer) {
   EXPECT_FALSE(active_layer_->needs_post_commit_initialization());
 }
 
+TEST_F(PictureLayerImplTest, SyncTilingAfterReleaseResource) {
+  SetupDefaultTrees(gfx::Size(10, 10));
+  host_impl_.active_tree()->UpdateDrawProperties();
+  EXPECT_FALSE(host_impl_.active_tree()->needs_update_draw_properties());
+
+  // Contrived unit test of a real crash. A layer is transparent during a
+  // context loss, and later becomes opaque, causing active layer SyncTiling to
+  // be called.
+  const float tile_scale = 2.f;
+  active_layer_->DidLoseOutputSurface();
+  EXPECT_FALSE(active_layer_->tilings()->TilingAtScale(tile_scale));
+  pending_layer_->AddTiling(2.f);
+  EXPECT_TRUE(active_layer_->tilings()->TilingAtScale(tile_scale));
+}
+
 class DeferredInitPictureLayerImplTest : public PictureLayerImplTest {
  public:
   DeferredInitPictureLayerImplTest()