Pop up only one dialog box for gpu-startup-dialog command flag.

There are two gpu processes on Windows - a sandboxed for the main gpu
functions and another short-lived unsandboxed for gpu info collection.
Currently, both gpu process pid boxes pop up for gpu-startup-dialog command
flag. To avoid confusion, this CL allows the pop-up of the main sandboxed
gpu process pid only.

enum GpuProcessKind is moved from gpu_process_host.h to gpu_data_manager.h


Bug:961662

Change-Id: Ic5c161013ad6bde60ceb06be7ac51270ca9254f7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1606771
Commit-Queue: Antoine Labour <piman@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#660259}
18 files changed