gpu_process_launch_causes => content/common

This is used to establish the channel and has content-speciifc concepts.
This doesn't seem to belong to content/common/gpu as per piman@'s suggestion.

BUG=596290
CQ_INCLUDE_TRYBOTS=tryserver.chromium.win:win_optional_gpu_tests_rel

Review URL: https://codereview.chromium.org/1825183002

Cr-Commit-Position: refs/heads/master@{#382724}
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index fc6734c..cf98faf 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -26,6 +26,7 @@
 #include "content/common/content_export.h"
 #include "content/common/frame_replication_state.h"
 #include "content/common/gpu/client/gpu_channel_host.h"
+#include "content/common/gpu_process_launch_causes.h"
 #include "content/common/storage_partition_service.mojom.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/renderer/gpu/compositor_dependencies.h"