exo: Validate cmd line params for yuv wayland client

The --use-drm parameter is required to allocate buffers that have a
valid bo inside of them which is used by the yuv client.

Bug: None
Test: Ran wayland_yuv_client w/ and w/out --use-drm param
Change-Id: I29027ee4608da05ed82aeb03f6e8b63713df32ff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1914759Reviewed-by: Daniele Castagna <dcastagna@chromium.org>
Commit-Queue: Daniele Castagna <dcastagna@chromium.org>
Cr-Commit-Position: refs/heads/master@{#715061}

components/exo/wayland/clients/yuv.cc

@@ -132,6 +132,12 @@ int main(int argc, char* argv[]) {
   if (!params.FromCommandLine(*command_line))
     return 1;
 
+  if (!params.use_drm) {
+    LOG(ERROR) << "Missing --use-drm parameter which is required for buffer "
+                  "allocation";
+    return 1;
+  }
+
   // TODO(dcastagna): Support other YUV formats.
   params.drm_format = DRM_FORMAT_NV12;
   params.bo_usage =
@@ -140,5 +146,5 @@ int main(int argc, char* argv[]) {
   base::SingleThreadTaskExecutor main_task_executor(base::MessagePumpType::UI);
   exo::wayland::clients::YuvClient client;
   client.Run(params);
-  return 1;
+  return 0;
 }