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 56539d110a0be39f2d8541e7f1f3b7ff05023578..cf786120dcc31e542652da81ecd1f88198329838 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -1185,6 +1185,10 @@ void LayerTreeHostImpl::UpdateTileManagerMemoryPolicy(
           gpu::MemoryAllocation::CUTOFF_ALLOW_NOTHING);
   global_tile_state_.num_resources_limit = policy.num_resources_limit;
 
+  if (use_gpu_rasterization_ && resource_provider_ &&
+      (!visible_ || global_tile_state_.hard_memory_limit_in_bytes == 0))
+    resource_provider_->FreeGrResources();
+
   // 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