cc: Free gpu resources when we are invisible or TM is oom.

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 f81a3b1d74f84ca0fca917b7f1830bb3687af138..a176a02a3b993c9067ed588a489c63bf492d2905 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -1169,6 +1169,12 @@ void LayerTreeHostImpl::UpdateTileManagerMemoryPolicy(
           gpu::MemoryAllocation::CUTOFF_ALLOW_NOTHING);
   global_tile_state_.num_resources_limit = policy.num_resources_limit;
 
+  if (use_gpu_rasterization_ &&
+      (!visible_ || global_tile_state_.hard_memory_limit_in_bytes == 0)) {
+    if (rasterizer_)
+      rasterizer_->ClearCache();
+  }
+
   // TODO(reveman): We should avoid keeping around unused resources if
   // possible. crbug.com/224475
   // Unused limit is calculated from soft-limit, as hard-limit may