UI resource are evicted when LTH is set to not visible.

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index cb76b46769dc7bb82f0c7cedf9e4fe06a326d402..5c3a0572c119786dbe5c2da0f2670556dfd4f5e5 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -435,7 +435,8 @@ void LayerTreeHost::DidLoseOutputSurface() {
   if (output_surface_lost_)
     return;
 
-  DidLoseUIResources();
+  bool resource_lost = true;

[ccameron, 2013/08/26 23:54:32]

I haven't seen this way for naming a parameter before -- someone closer to cc/
should comment on if this is okay. Might want to use an enum.

[danakj, 2013/08/27 00:30:03]

This is generally how we pass bool literals, ie we don't pass "true/false"
directly to a function without a name unless it's super obvious what it means.
An enum could work too, but maybe overkill IMO.

+  RecreateUIResources(resource_lost);
 
   num_failed_recreate_attempts_ = 0;
   output_surface_lost_ = true;
@@ -626,8 +627,13 @@ void LayerTreeHost::SetVisible(bool visible) {
   if (visible_ == visible)
     return;
   visible_ = visible;
-  if (!visible)
+  if (!visible) {
     ReduceMemoryUsage();
+  } else {
+    // Recreate the UI resources since they were evicted when SetVisible(false).
+    bool resource_lost = false;
+    RecreateUIResources(resource_lost);
+  }
   proxy_->SetVisible(visible);
 }
 
@@ -1155,26 +1161,18 @@ void LayerTreeHost::DeleteUIResource(UIResourceId uid) {
   ui_resource_client_map_.erase(uid);
 }
 
-void LayerTreeHost::UIResourceLost(UIResourceId uid) {
-  UIResourceClientMap::iterator iter = ui_resource_client_map_.find(uid);
-  if (iter == ui_resource_client_map_.end())
-    return;
-
-  UIResourceRequest request;
-  bool resource_lost = true;
-  request.type = UIResourceRequest::UIResourceCreate;
-  request.id = uid;
-  request.bitmap = iter->second->GetBitmap(uid, resource_lost);
-  DCHECK(request.bitmap.get());
-  ui_resource_request_queue_.push_back(request);
-}
-
-void LayerTreeHost::DidLoseUIResources() {
+void LayerTreeHost::RecreateUIResources(bool resource_lost) {
   // When output surface is lost, we need to recreate the resource.
   for (UIResourceClientMap::iterator iter = ui_resource_client_map_.begin();
        iter != ui_resource_client_map_.end();
        ++iter) {
-    UIResourceLost(iter->first);
+    UIResourceId uid = iter->first;
+    UIResourceRequest request;
+    request.type = UIResourceRequest::UIResourceCreate;
+    request.id = uid;
+    request.bitmap = iter->second->GetBitmap(uid, resource_lost);
+    DCHECK(request.bitmap.get());
+    ui_resource_request_queue_.push_back(request);
   }
 }