cc: Control activation from the Scheduler

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 9f664fcc0ee40385784ff1cf74c61cc32fcf5371..487984ed296c9d35d08559d97177ea04a7b1147e 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -110,12 +110,8 @@ class LayerTreeHostImplTimeSourceAdapter : public TimeSourceClient {
 
     // TODO(enne): This should probably happen post-animate.
     if (layer_tree_host_impl_->pending_tree()) {
-      layer_tree_host_impl_->ActivatePendingTreeIfNeeded();
-
-      if (layer_tree_host_impl_->pending_tree()) {
-        layer_tree_host_impl_->pending_tree()->UpdateDrawProperties();
-        layer_tree_host_impl_->ManageTiles();
-      }
+      layer_tree_host_impl_->pending_tree()->UpdateDrawProperties();
+      layer_tree_host_impl_->ManageTiles();
     }
 
     layer_tree_host_impl_->Animate(
@@ -176,6 +172,8 @@ LayerTreeHostImpl::LayerTreeHostImpl(
       should_bubble_scrolls_(false),
       wheel_scrolling_(false),
       manage_tiles_needed_(false),
+      block_notify_ready_to_activate_for_testing_(false),

[enne (OOO), 2013/08/26 21:57:52]

I kind of liked the previous interposer in that it kept the testing code out of
production code.  Could you move this LTHI code to some derived LTHI type and
move the block tracking there?

[brianderson, 2013/08/26 22:47:26]

I will put the code into LayerTreeHostImplForTesting, which is where a lot of
this kind of stuff already lives. I would be tempted to keep the client proxy if
it had more uses that couldn't be implemented in LayerTreeHostImplForTesting.

I will still need a stub implementation of
LayerTreeHostImpl::BlockNotifyReadyToActivateForTesting, for which I will just
call NOTREACHED().

+      notify_ready_to_activate_was_blocked_(false),
       root_layer_scroll_offset_delegate_(NULL),
       settings_(settings),
       visible_(true),
@@ -254,7 +252,10 @@ void LayerTreeHostImpl::CommitComplete() {
     pending_tree_->set_needs_update_draw_properties();
     pending_tree_->UpdateDrawProperties();
     // Start working on newly created tiles immediately if needed.
-    ManageTiles();
+    if (!manage_tiles_needed_)
+      NotifyReadyToActivate();
+    else
+      ManageTiles();
   } else {
     active_tree_->set_needs_update_draw_properties();
   }
@@ -1026,6 +1027,18 @@ void LayerTreeHostImpl::EvictTexturesForTesting() {
   EnforceManagedMemoryPolicy(ManagedMemoryPolicy(0));
 }
 
+
+void LayerTreeHostImpl::BlockNotifyReadyToActivateForTesting(bool block) {
+  UNSHIPPED_TRACE_EVENT1(
+      "cc", "LayerTreeHostImpl::BlockNotifyReadyToActivateForTesting",
+      "block", block);
+  block_notify_ready_to_activate_for_testing_ = block;
+  if (!block && notify_ready_to_activate_was_blocked_) {
+    NotifyReadyToActivate();
+    notify_ready_to_activate_was_blocked_ = false;
+  }
+}
+
 void LayerTreeHostImpl::EnforceManagedMemoryPolicy(
     const ManagedMemoryPolicy& policy) {
 
@@ -1085,10 +1098,10 @@ void LayerTreeHostImpl::DidInitializeVisibleTile() {
 }
 
 void LayerTreeHostImpl::NotifyReadyToActivate() {
-  if (pending_tree_) {
-    need_to_update_visible_tiles_before_draw_ = true;
-    ActivatePendingTree();
-  }
+  if (block_notify_ready_to_activate_for_testing_)
+    notify_ready_to_activate_was_blocked_ = true;
+  else
+    client_->NotifyReadyToActivate();
 }
 
 bool LayerTreeHostImpl::ShouldClearRootRenderPass() const {
@@ -1433,7 +1446,6 @@ void LayerTreeHostImpl::CreatePendingTree() {
   else
     pending_tree_ = LayerTreeImpl::create(this);
   client_->OnCanDrawStateChanged(CanDraw());
-  client_->OnHasPendingTreeStateChanged(pending_tree_);
   TRACE_EVENT_ASYNC_BEGIN0("cc", "PendingTree", pending_tree_.get());
   TRACE_EVENT_ASYNC_STEP0("cc",
                           "PendingTree", pending_tree_.get(), "waiting");
@@ -1449,33 +1461,12 @@ void LayerTreeHostImpl::UpdateVisibleTiles() {
   need_to_update_visible_tiles_before_draw_ = false;
 }
 
-void LayerTreeHostImpl::ActivatePendingTreeIfNeeded() {
-  DCHECK(pending_tree_);
-  CHECK(settings_.impl_side_painting);
-
-  if (!pending_tree_)
-    return;
-
-  // The tile manager is usually responsible for notifying activation.
-  // If there is no tile manager, then we need to manually activate.
-  if (!tile_manager_ || tile_manager_->AreTilesRequiredForActivationReady()) {
-    ActivatePendingTree();
-    return;
-  }
-
-  // Manage tiles in case state affecting tile priority has changed.
-  ManageTiles();
-
-  TRACE_EVENT_ASYNC_STEP1(
-    "cc",
-    "PendingTree", pending_tree_.get(), "activate",
-    "state", TracedValue::FromValue(ActivationStateAsValue().release()));
-}
-
 void LayerTreeHostImpl::ActivatePendingTree() {
   CHECK(pending_tree_);
   TRACE_EVENT_ASYNC_END0("cc", "PendingTree", pending_tree_.get());
 
+  need_to_update_visible_tiles_before_draw_ = true;
+
   active_tree_->SetRootLayerScrollOffsetDelegate(NULL);
   active_tree_->PushPersistedState(pending_tree_.get());
   if (pending_tree_->needs_full_tree_sync()) {
@@ -1504,12 +1495,15 @@ void LayerTreeHostImpl::ActivatePendingTree() {
       root_layer_scroll_offset_delegate_);
   active_tree_->DidBecomeActive();
 
+  client_->DidActivatePendingTree();
+  if (!tree_activation_callback_.is_null())
+    tree_activation_callback_.Run();
+
   // Reduce wasted memory now that unlinked resources are guaranteed not
   // to be used.
   client_->ReduceWastedContentsTextureMemoryOnImplThread();
 
   client_->OnCanDrawStateChanged(CanDraw());
-  client_->OnHasPendingTreeStateChanged(pending_tree_);
   client_->SetNeedsRedrawOnImplThread();
   client_->RenewTreePriority();
 
@@ -1520,10 +1514,6 @@ void LayerTreeHostImpl::ActivatePendingTree() {
         stats.main_stats.paint_time + stats.main_stats.record_time +
             stats.impl_stats.rasterize_time_for_now_bins_on_pending_tree);
   }
-
-  client_->DidActivatePendingTree();
-  if (!tree_activation_callback_.is_null())
-    tree_activation_callback_.Run();
 }
 
 void LayerTreeHostImpl::SetVisible(bool visible) {