Make bounds editable through the CSS sidepanel

ash/common/wm_shell.cc

Index: ash/common/wm_shell.cc
diff --git a/ash/common/wm_shell.cc b/ash/common/wm_shell.cc
index 012ac5e6800869a3660988d7740d35634fbf1b46..64a0e3a923117718f6acc053b43bd200b3efaa41 100644
--- a/ash/common/wm_shell.cc
+++ b/ash/common/wm_shell.cc
@@ -95,8 +95,8 @@ void WmShell::Initialize(const scoped_refptr<base::SequencedWorkerPool>& pool) {
   if (devtools_server_) {
     auto dom_backend = base::MakeUnique<devtools::AshDevToolsDOMAgent>(
         this, base::MessageLoop::current()->task_runner());
-    auto css_backend =
-        base::MakeUnique<devtools::AshDevToolsCSSAgent>(dom_backend.get());
+    auto css_backend = base::MakeUnique<devtools::AshDevToolsCSSAgent>(
+        dom_backend.get(), base::MessageLoop::current()->task_runner());
     auto devtools_client = base::MakeUnique<ui::devtools::UiDevToolsClient>(
         "Ash", devtools_server_.get());
     devtools_client->AddAgent(std::move(dom_backend));