ozone: Allow cursor requests to come in before the drm thread comes up.

ui/ozone/platform/drm/ozone_platform_gbm.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/ozone/platform/drm/ozone_platform_gbm.h"
 
 #include <dlfcn.h>
 #include <fcntl.h>
 #include <gbm.h>
 #include <stdlib.h>
@@ skipping 92 matching lines @@
   }
   GpuPlatformSupportHost* GetGpuPlatformSupportHost() override {
     return gpu_platform_support_host_.get();
   }
   std::unique_ptr<SystemInputInjector> CreateSystemInputInjector() override {
     return event_factory_ozone_->CreateSystemInputInjector();
   }
   void AddInterfaces(shell::InterfaceRegistry* registry) override {
     registry->AddInterface<ozone::mojom::DeviceCursor>(this);
   }
-  // shell::InterfaceFactory<mojom::ozone::Cursor> implementation.
+  // shell::InterfaceFactory<ozone::mojom::DeviceCursor> implementation.
   void Create(const shell::Identity& remote_identity,
               ozone::mojom::DeviceCursorRequest request) override {
-    DCHECK(drm_thread_proxy_);
-    drm_thread_proxy_->AddBinding(std::move(request));
+    if (drm_thread_proxy_)
+      drm_thread_proxy_->AddBinding(std::move(request));
+    else
+      pending_cursor_requests_.push_back(std::move(request));
   }
   std::unique_ptr<PlatformWindow> CreatePlatformWindow(
       PlatformWindowDelegate* delegate,
       const gfx::Rect& bounds) override {
     GpuThreadAdapter* adapter = gpu_platform_support_host_.get();
     if (using_mojo_ || single_process_) {
       DCHECK(drm_thread_proxy_)
           << "drm_thread_proxy_ should exist (and be running) here.";
       adapter = mus_thread_proxy_.get();
     }
@@ skipping 100 matching lines @@
 
     // NOTE: Can't start the thread here since this is called before sandbox
     // initialization in multi-process Chrome. In mus, we start the DRM thread.
     drm_thread_proxy_.reset(new DrmThreadProxy());
     drm_thread_proxy_->BindThreadIntoMessagingProxy(itmp);
 
     surface_factory_.reset(new GbmSurfaceFactory(drm_thread_proxy_.get()));
     if (using_mojo_ || single_process_) {
       mus_thread_proxy_->StartDrmThread();
     }
+    for (auto& request : pending_cursor_requests_)
+      drm_thread_proxy_->AddBinding(std::move(request));
+    pending_cursor_requests_.clear();
   }
 
  private:
   bool using_mojo_;
   bool single_process_;
 
   // Objects in the GPU process.
   std::unique_ptr<DrmThreadProxy> drm_thread_proxy_;
   std::unique_ptr<GlApiLoader> gl_api_loader_;
   std::unique_ptr<GbmSurfaceFactory> surface_factory_;
   scoped_refptr<IPC::MessageFilter> gpu_message_filter_;
+  // TODO(sad): Once the mus gpu process split happens, this can go away.
+  std::vector<ozone::mojom::DeviceCursorRequest> pending_cursor_requests_;
 
   // Objects in the Browser process.
   std::unique_ptr<DeviceManager> device_manager_;
   std::unique_ptr<BitmapCursorFactoryOzone> cursor_factory_ozone_;
   std::unique_ptr<DrmWindowHostManager> window_manager_;
   std::unique_ptr<DrmCursor> cursor_;
   std::unique_ptr<EventFactoryEvdev> event_factory_ozone_;
   std::unique_ptr<DrmGpuPlatformSupportHost> gpu_platform_support_host_;
   std::unique_ptr<DrmDisplayHostManager> display_manager_;
   std::unique_ptr<DrmOverlayManager> overlay_manager_;
 
   // Bridges the DRM, GPU and main threads in mus.
   std::unique_ptr<MusThreadProxy> mus_thread_proxy_;
 
 #if defined(USE_XKBCOMMON)
   XkbEvdevCodes xkb_evdev_code_converter_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(OzonePlatformGbm);
 };
 
 }  // namespace
 
 OzonePlatform* CreateOzonePlatformGbm() {
   return new OzonePlatformGbm;
 }
 
 }  // namespace ui