Re-land: cc: Examine layers to determine if we're ready to activate.

This introduces a new mechanism for determining when
we're ready to activate the pending tree. The tile
priority is still used to determine when it's worth
waking up the compositor thread and evaluating if
we can activate. However, the actual check that
determines if we're ready to activate doesn't rely
on the state of scheduled raster tasks but is a
synchronous call on each layer.

The result is a pending tree activation mechanism that
is much easier to debug and validate for correctness,
while still providing the performance benefits of the
old mechanism by taking the "required to activate" field
of the tile priority into account when scheduling tasks.
 
BUG=375206
TEST=cc_unittests --gtest_filter=PictureLayerImplTest.AllTilesRequiredForActivationAreReadyToDraw

Review URL: https://codereview.chromium.org/287643004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@273040 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 56 insertions, 0 deletions

diff --git a/cc/layers/picture_layer_impl_unittest.cc b/cc/layers/picture_layer_impl_unittest.cc
index d919298..64454ae 100644
--- a/cc/layers/picture_layer_impl_unittest.cc
+++ b/cc/layers/picture_layer_impl_unittest.cc
@@ -2391,5 +2391,61 @@ TEST_F(PictureLayerImplTest, RasterScaleChangeWithoutAnimation) {
   EXPECT_BOTH_EQ(HighResTiling()->contents_scale(), 1.f);
 }
 
+TEST_F(PictureLayerImplTest, LowResReadyToDrawNotEnoughToActivate) {
+  gfx::Size tile_size(100, 100);
+  gfx::Size layer_bounds(1000, 1000);
+
+  SetupDefaultTreesWithFixedTileSize(layer_bounds, tile_size);
+
+  // Make sure some tiles are not shared.
+  pending_layer_->set_invalidation(gfx::Rect(gfx::Point(50, 50), tile_size));
+
+  CreateHighLowResAndSetAllTilesVisible();
+  active_layer_->SetAllTilesReady();
+  pending_layer_->MarkVisibleResourcesAsRequired();
+
+  // All pending layer tiles required are not ready.
+  EXPECT_FALSE(pending_layer_->AllTilesRequiredForActivationAreReadyToDraw());
+
+  // Initialize all low-res tiles.
+  pending_layer_->SetAllTilesReadyInTiling(pending_layer_->LowResTiling());
+
+  // Low-res tiles should not be enough.
+  EXPECT_FALSE(pending_layer_->AllTilesRequiredForActivationAreReadyToDraw());
+
+  // Initialize remaining tiles.
+  pending_layer_->SetAllTilesReady();
+
+  EXPECT_TRUE(pending_layer_->AllTilesRequiredForActivationAreReadyToDraw());
+}
+
+TEST_F(PictureLayerImplTest, HighResReadyToDrawNotEnoughToActivate) {
+  gfx::Size tile_size(100, 100);
+  gfx::Size layer_bounds(1000, 1000);
+
+  SetupDefaultTreesWithFixedTileSize(layer_bounds, tile_size);
+
+  // Make sure some tiles are not shared.
+  pending_layer_->set_invalidation(gfx::Rect(gfx::Point(50, 50), tile_size));
+
+  CreateHighLowResAndSetAllTilesVisible();
+  active_layer_->SetAllTilesReady();
+  pending_layer_->MarkVisibleResourcesAsRequired();
+
+  // All pending layer tiles required are not ready.
+  EXPECT_FALSE(pending_layer_->AllTilesRequiredForActivationAreReadyToDraw());
+
+  // Initialize all high-res tiles.
+  pending_layer_->SetAllTilesReadyInTiling(pending_layer_->HighResTiling());
+
+  // High-res tiles should not be enough.
+  EXPECT_FALSE(pending_layer_->AllTilesRequiredForActivationAreReadyToDraw());
+
+  // Initialize remaining tiles.
+  pending_layer_->SetAllTilesReady();
+
+  EXPECT_TRUE(pending_layer_->AllTilesRequiredForActivationAreReadyToDraw());
+}
+
 }  // namespace
 }  // namespace cc