[ozone] Temporary workaround for GPU support message filter not being installed early enough.

Some initial messages may get routed to main thread. Once we get
our first message on io, send it to main to ensure all prior main
thread operations are finished before we continue on io.

BUG=446184

Review URL: https://codereview.chromium.org/801233003

Cr-Commit-Position: refs/heads/master@{#311497}

ui/ozone/platform/dri/dri_gpu_platform_support.cc

@@ -34,7 +34,8 @@ class DriGpuPlatformSupportMessageFilter : public IPC::MessageFilter {
         main_thread_listener_(main_thread_listener),
         main_thread_task_runner_(base::ThreadTaskRunnerHandle::Get()),
         pending_main_thread_operations_(0),
-        cursor_animating_(false) {}
+        cursor_animating_(false),
+        start_on_main_(true) {}
 
   void OnFilterAdded(IPC::Sender* sender) override {
     io_thread_task_runner_ = base::ThreadTaskRunnerHandle::Get();
@@ -59,7 +60,8 @@ class DriGpuPlatformSupportMessageFilter : public IPC::MessageFilter {
     bool cursor_was_animating = cursor_animating_;
     UpdateAnimationState(message);
     if (cursor_state_message || pending_main_thread_operations_ ||
-        cursor_animating_ || cursor_was_animating) {
+        cursor_animating_ || cursor_was_animating || start_on_main_) {
+      start_on_main_ = false;
       pending_main_thread_operations_++;
 
       base::Closure main_thread_message_handler =
@@ -151,6 +153,12 @@ class DriGpuPlatformSupportMessageFilter : public IPC::MessageFilter {
   scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner_;
   int32 pending_main_thread_operations_;
   bool cursor_animating_;
+  // The filter is not installed early enough, so some messages may
+  // get routed to main thread. Once we get our first message on io, send it
+  // to main to ensure all prior main thread operations are finished before we
+  // continue on io.
+  // TODO: remove this once filter is properly installed.
+  bool start_on_main_;
 };
 }