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

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 1131050dc695a131dfee529af78852843b05ae7e..cc72e84bb27ec308b0c20c70da47b62ee285d90e 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -1536,11 +1536,15 @@ void LayerTreeHostImpl::SetVisible(bool visible) {
   DidVisibilityChange(this, visible_);
   EnforceManagedMemoryPolicy(ActualManagedMemoryPolicy());
 
-  // Evict tiles immediately if invisible since this tab may never get another
-  // draw or timer tick.
-  if (!visible_)
+  if (!visible_) {
+    // Evict tiles immediately if invisible since this tab may never get another
+    // draw or timer tick.
     ManageTiles();
 
+    // Evict UI resources
+    ReleaseUIResources();
+  }
+
   if (!renderer_)
     return;
 
@@ -1576,8 +1580,7 @@ void LayerTreeHostImpl::ReleaseTreeResources() {
   if (recycle_tree_ && recycle_tree_->root_layer())
     SendReleaseResourcesRecursive(recycle_tree_->root_layer());
 
-  // Remove all existing maps from UIResourceId to ResourceId.
-  ui_resource_map_.clear();
+  ReleaseUIResources();
 }
 
 void LayerTreeHostImpl::CreateAndSetRenderer(
@@ -2548,4 +2551,13 @@ ResourceProvider::ResourceId LayerTreeHostImpl::ResourceIdForUIResource(
   return 0;
 }
 
+void LayerTreeHostImpl::ReleaseUIResources() {
+  for (UIResourceMap::const_iterator iter = ui_resource_map_.begin();
+      iter != ui_resource_map_.end();
+      ++iter) {
+    resource_provider_->DeleteResource(iter->second);
+  }
+  ui_resource_map_.clear();
+}
+
 }  // namespace cc