Ozone/DRM: Fix DCHECK due to blocking on WaitableEvent

Add base::ScopedAllowBaseSyncPrimitivesOutsideBlockingScope to all
methods in DrmThreadProxy that block.

Fixed: 1047827
Change-Id: I0ff3239d85264244dd6f5a0098ee18daa3c4960e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2033633
Commit-Queue: Saman Sami <samans@chromium.org>
Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
Reviewed-by: kylechar <kylechar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738266}

base/threading/thread_restrictions.h

@@ -219,6 +219,7 @@ class ModelSafeWorker;
 namespace ui {
 class CommandBufferClientImpl;
 class CommandBufferLocal;
+class DrmThreadProxy;
 class GpuState;
 class MaterialDesignController;
 }
@@ -499,6 +500,7 @@ class BASE_EXPORT ScopedAllowBaseSyncPrimitivesOutsideBlockingScope {
   friend class media::PaintCanvasVideoRenderer;
   friend class mojo::SyncCallRestrictions;
   friend class net::NetworkConfigWatcherMacThread;
+  friend class ui::DrmThreadProxy;
   friend class viz::HostGpuMemoryBufferManager;
   friend class vr::VrShell;
 

ui/ozone/platform/drm/gpu/drm_thread_proxy.cc

@@ -88,6 +88,7 @@ void DrmThreadProxy::CreateBuffer(gfx::AcceleratedWidget widget,
   TRACE_EVENT0("drm", "DrmThreadProxy::CreateBuffer");
   DCHECK(drm_thread_.task_runner())
       << "no task runner! in DrmThreadProxy::CreateBuffer";
+  base::ScopedAllowBaseSyncPrimitivesOutsideBlockingScope allow_wait;
   base::OnceClosure task =
       base::BindOnce(&DrmThread::CreateBuffer, base::Unretained(&drm_thread_),
                      widget, size, format, usage, flags, buffer, framebuffer);
@@ -129,6 +130,7 @@ void DrmThreadProxy::CreateBufferFromHandle(
     std::unique_ptr<GbmBuffer>* buffer,
     scoped_refptr<DrmFramebuffer>* framebuffer) {
   TRACE_EVENT0("drm", "DrmThreadProxy::CreateBufferFromHandle");
+  base::ScopedAllowBaseSyncPrimitivesOutsideBlockingScope allow_wait;
   base::OnceClosure task = base::BindOnce(
       &DrmThread::CreateBufferFromHandle, base::Unretained(&drm_thread_),
       widget, size, format, std::move(handle), buffer, framebuffer);
@@ -169,6 +171,7 @@ std::vector<OverlayStatus> DrmThreadProxy::CheckOverlayCapabilitiesSync(
     const std::vector<OverlaySurfaceCandidate>& candidates) {
   TRACE_EVENT0("drm", "DrmThreadProxy::CheckOverlayCapabilitiesSync");
   DCHECK(drm_thread_.task_runner());
+  base::ScopedAllowBaseSyncPrimitivesOutsideBlockingScope allow_wait;
   std::vector<OverlayStatus> result;
   base::OnceClosure task = base::BindOnce(
       &DrmThread::CheckOverlayCapabilitiesSync, base::Unretained(&drm_thread_),