Terminate GPU process via ExitProcess rather than RunLoop::QuitCurrent.

Quitting the RunLoop with QuitCurrent*Deprecated() triggers the DCHECK
against mixing the deprecated quit APIs with use of QuitClosure.

Use the GpuServiceImpl::ExitProcess() helper to quit the process
gracefully, instead.

Also removes the |is_exiting_| flag in favour of checking whether
|exit_callback_| is set, and adds a DCHECK for a non-null
|exit_callback| being passed at construction.

Bug: 882068
Cq-Include-Trybots: luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: Id8a87e4648fbac3283f41ce2f80cf03a153227ab
Reviewed-on: https://chromium-review.googlesource.com/1214750
Commit-Queue: Wez <wez@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#590061}

components/viz/service/gl/gpu_service_impl.cc

@@ -12,7 +12,6 @@
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/memory/shared_memory.h"
-#include "base/run_loop.h"
 #include "base/task/post_task.h"
 #include "base/task_runner_util.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ -159,6 +158,8 @@ GpuServiceImpl::GpuServiceImpl(
       bindings_(std::make_unique<mojo::BindingSet<mojom::GpuService>>()),
       weak_ptr_factory_(this) {
   DCHECK(!io_runner_->BelongsToCurrentThread());
+  DCHECK(exit_callback_);
+
 #if defined(OS_CHROMEOS)
   protected_buffer_manager_ = new arc::ProtectedBufferManager();
 #endif  // defined(OS_CHROMEOS)
@@ -540,9 +541,8 @@ void GpuServiceImpl::GetGpuSupportedRuntimeVersion(
   gpu::RecordGpuSupportedRuntimeVersionHistograms(&gpu_info_);
   std::move(callback).Run(gpu_info_);
   if (!in_host_process()) {
-    // The unsandboxed GPU process fulfilled its duty. Rest
-    // in peace.
-    base::RunLoop().QuitCurrentWhenIdleDeprecated();
+    // The unsandboxed GPU process fulfilled its duty. Bye bye.
+    ExitProcess();
   }
 #endif
 }
@@ -566,9 +566,8 @@ void GpuServiceImpl::RequestCompleteGpuInfo(
             std::move(callback).Run(gpu_service->gpu_info_);
 #if defined(OS_WIN)
             if (!gpu_service->in_host_process()) {
-              // The unsandboxed GPU process fulfilled its duty. Rest
-              // in peace.
-              base::RunLoop::QuitCurrentWhenIdleDeprecated();
+              // The unsandboxed GPU process fulfilled its duty. Bye bye.
+              gpu_service->ExitProcess();
             }
 #endif
           },
@@ -684,11 +683,8 @@ void GpuServiceImpl::StoreShaderToDisk(int client_id,
 }
 
 void GpuServiceImpl::ExitProcess() {
-  if (is_exiting_)
-    return;
-
-  is_exiting_ = true;
-  std::move(exit_callback_).Run();
+  if (exit_callback_)
+    std::move(exit_callback_).Run();
 }
 
 #if defined(OS_WIN)

components/viz/service/gl/gpu_service_impl.h

@@ -301,7 +301,6 @@ class VIZ_SERVICE_EXPORT GpuServiceImpl : public gpu::GpuChannelManagerDelegate,
 
   // Callback that safely exits GPU process.
   base::OnceClosure exit_callback_;
-  bool is_exiting_ = false;
 
   base::Time start_time_;
 

components/viz/service/main/viz_main_impl.h

@@ -78,8 +78,6 @@ class VizMainImpl : public gpu::GpuSandboxHelper, public mojom::VizMain {
     DISALLOW_COPY_AND_ASSIGN(ExternalDependencies);
   };
 
-  // TODO(kylechar): Provide a quit closure for the appropriate RunLoop instance
-  // to stop the thread and remove base::RunLoop::QuitCurrentDeprecated() usage.
   VizMainImpl(Delegate* delegate,
               ExternalDependencies dependencies,
               std::unique_ptr<gpu::GpuInit> gpu_init = nullptr);