memory-infra: move SUMMARY_ONLY from type to level of detail

As with VM_REGIONS_ONLY, SUMMARY_ONLY never belonged in the type enum as
its meaning refers how much information should be returned to the caller
of the memory instrumentation service.

Move the enum member and change all relevant references. Eventually, we
plan to remove this member all together as its purpose will be subsumed
by one of the other levels of detail but for now this is a good stepping
stone.

Bug: 775041
Bug: 777820
Change-Id: I43504be0cd2f864b38dfd607b7d08ada156ed7ca
Reviewed-on: https://chromium-review.googlesource.com/735700
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Primiano Tucci <primiano@chromium.org>
Reviewed-by: Siddhartha S <ssid@chromium.org>
Commit-Queue: Lalit Maganti <lalitm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#511645}

• base/trace_event/memory_dump_manager.cc[diff]
• base/trace_event/memory_dump_manager_unittest.cc[diff]
• base/trace_event/memory_dump_request_args.cc[diff]
• base/trace_event/memory_dump_request_args.h[diff]
• base/trace_event/memory_dump_scheduler.cc[diff]
• chrome/browser/metrics/process_memory_metrics_emitter.cc[diff]
• services/resource_coordinator/memory_instrumentation/coordinator_impl_unittest.cc[diff]
• services/resource_coordinator/memory_instrumentation/queued_request.h[diff]
• services/resource_coordinator/public/cpp/memory_instrumentation/memory_instrumentation.cc[diff]
• services/resource_coordinator/public/cpp/memory_instrumentation/memory_instrumentation_struct_traits.cc[diff]
• services/resource_coordinator/public/cpp/memory_instrumentation/struct_traits_unittest.cc[diff]
• services/resource_coordinator/public/cpp/memory_instrumentation/tracing_observer.cc[diff]
• services/resource_coordinator/public/interfaces/memory_instrumentation/memory_instrumentation.mojom[diff]