[cc] Evict UIResources when the renderer is 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 773a689ac03749590685580a88dafb9cb92fcf0b..3b9da9006ce597344079868c5d94788b7bdb78d7 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -62,7 +62,10 @@ RendererCapabilities::RendererCapabilities()
 RendererCapabilities::~RendererCapabilities() {}
 
 UIResourceRequest::UIResourceRequest()
-    : type(UIResourceInvalidRequest), id(0), bitmap(NULL) {}
+    : type(UIResourceInvalidRequest),
+      id(0),
+      bitmap(NULL),
+      eviction_count_recreated(0) {}
 
 UIResourceRequest::~UIResourceRequest() {}
 
@@ -86,6 +89,7 @@ static int s_next_tree_id = 1;
 LayerTreeHost::LayerTreeHost(LayerTreeHostClient* client,
                              const LayerTreeSettings& settings)
     : next_ui_resource_id_(1),
+      ui_resource_eviction_count_recreated_(0),
       animating_(false),
       needs_full_tree_sync_(true),
       needs_filter_context_(false),
@@ -379,6 +383,13 @@ void LayerTreeHost::FinishCommitOnImplThread(LayerTreeHostImpl* host_impl) {
         overhang_ui_resource_->GetSize());
   }
 
+  // If all UI resource evictions will not be recreated by this commit, then
+  // another commit is required.
+  if (ui_resource_eviction_count_recreated_ !=
+      host_impl->ui_resource_eviction_count()) {
+    host_impl->SetNeedsCommit();
+  }
+
   DCHECK(!sync_tree->ViewportSizeInvalid());
 
   if (new_impl_tree_has_no_evicted_resources) {
@@ -444,9 +455,6 @@ void LayerTreeHost::DidLoseOutputSurface() {
   if (output_surface_lost_)
     return;
 
-  bool resource_lost = true;
-  RecreateUIResources(resource_lost);
-
   num_failed_recreate_attempts_ = 0;
   output_surface_lost_ = true;
   SetNeedsCommit();
@@ -1176,7 +1184,11 @@ void LayerTreeHost::DeleteUIResource(UIResourceId uid) {
   ui_resource_client_map_.erase(uid);
 }
 
-void LayerTreeHost::RecreateUIResources(bool resource_lost) {
+bool LayerTreeHost::SetUIResourceEvictionCount(
+    uint64 ui_resource_eviction_count) {
+  if (ui_resource_eviction_count_recreated_ == ui_resource_eviction_count)
+    return false;
+
   for (UIResourceClientMap::iterator iter = ui_resource_client_map_.begin();
        iter != ui_resource_client_map_.end();
        ++iter) {
@@ -1184,10 +1196,18 @@ void LayerTreeHost::RecreateUIResources(bool resource_lost) {
     UIResourceRequest request;
     request.type = UIResourceRequest::UIResourceCreate;
     request.id = uid;
+    bool resource_lost = true;
     request.bitmap = iter->second->GetBitmap(uid, resource_lost);
     DCHECK(request.bitmap.get());
     ui_resource_request_queue_.push_back(request);
   }
+  UIResourceRequest request;
+  request.type = UIResourceRequest::UIResourceEvictionRecreated;
+  request.eviction_count_recreated = ui_resource_eviction_count;
+  ui_resource_request_queue_.push_back(request);
+  ui_resource_eviction_count_recreated_ = ui_resource_eviction_count;
+
+  return true;
 }
 
 }  // namespace cc