cc: Get rid of non-delegated rendering in most cc unit tests.

cc/trees/layer_tree_host_unittest_record_gpu_histogram.cc

Index: cc/trees/layer_tree_host_unittest_record_gpu_histogram.cc
diff --git a/cc/trees/layer_tree_host_unittest_record_gpu_histogram.cc b/cc/trees/layer_tree_host_unittest_record_gpu_histogram.cc
index f56109b077fa5a48813845f78feeefd84556a104..a9b1993bd2ee4c9a297886b265284d832761c1c2 100644
--- a/cc/trees/layer_tree_host_unittest_record_gpu_histogram.cc
+++ b/cc/trees/layer_tree_host_unittest_record_gpu_histogram.cc
@@ -12,7 +12,7 @@ namespace cc {
 namespace {
 
 TEST(LayerTreeHostRecordGpuHistogramTest, SingleThreaded) {
-  FakeLayerTreeHostClient host_client(FakeLayerTreeHostClient::DIRECT_3D);
+  FakeLayerTreeHostClient host_client;
   TestTaskGraphRunner task_graph_runner;
   LayerTreeSettings settings;
   std::unique_ptr<FakeLayerTreeHost> host =
@@ -23,7 +23,7 @@ TEST(LayerTreeHostRecordGpuHistogramTest, SingleThreaded) {
 }
 
 TEST(LayerTreeHostRecordGpuHistogramTest, Threaded) {
-  FakeLayerTreeHostClient host_client(FakeLayerTreeHostClient::DIRECT_3D);
+  FakeLayerTreeHostClient host_client;
   TestTaskGraphRunner task_graph_runner;
   LayerTreeSettings settings;
   std::unique_ptr<FakeLayerTreeHost> host = FakeLayerTreeHost::Create(