ozone: demo: Remove stall in VulkanRenderer

This shouldn't be needed as VulkanSwapChain is handling synchronization
internally.

And remove a missing calling to Destroy().

Bug: none
Test: ozone_demo --enable-vulkan on X11

Change-Id: I8f4be6dcefef9757ca6e51d5d85b1ede99c8ff35
Reviewed-on: https://chromium-review.googlesource.com/1115731Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Commit-Queue: Michael Spang <spang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570565}

ui/ozone/demo/vulkan_renderer.cc

@@ -28,6 +28,7 @@ VulkanRenderer::VulkanRenderer(gpu::VulkanImplementation* vulkan_implementation,
 
 VulkanRenderer::~VulkanRenderer() {
   surface_->Finish();
+  render_pass_->Destroy();
   surface_->Destroy();
   surface_.reset();
   device_queue_->Destroy();
@@ -102,9 +103,6 @@ void VulkanRenderer::RenderFrame() {
 
   CHECK_EQ(surface_->SwapBuffers(), gfx::SwapResult::SWAP_ACK);
 
-  // TODO(spang): Use a better synchronization strategy.
-  command_buffer->Wait(UINT64_MAX);
-
   PostRenderFrameTask();
 }