Fix flaky LayerTreeHostCopyRequestTestDeleteTexture test.

cc/trees/layer_tree_host_unittest_copyrequest.cc

Index: cc/trees/layer_tree_host_unittest_copyrequest.cc
diff --git a/cc/trees/layer_tree_host_unittest_copyrequest.cc b/cc/trees/layer_tree_host_unittest_copyrequest.cc
index cf8b1cd119a45e96a8dabff23c7679b3542212bf..23ec0736843b2f7ca9566e70c0f0fe45004065fa 100644
--- a/cc/trees/layer_tree_host_unittest_copyrequest.cc
+++ b/cc/trees/layer_tree_host_unittest_copyrequest.cc
@@ -814,6 +814,11 @@ class LayerTreeHostCopyRequestTestDeleteTexture
                 base::Unretained(this)));
         break;
       case 1:
+        // Copy requests cause a followup commit and draw without the separate
+        // RenderPass required. This changes the number of active textures. So
+        // wait for that draw before counting textures and proceeding.
+        break;
+      case 2:
         // We did a readback, so there will be a readback texture around now.
         num_textures_after_readback_ =
             display_context_provider_->TestContext3d()->NumTextures();