Partly blocked on easy access to NavigationId from more places. crbug/754889

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/04652db4dfdd8c3663b50371a5f36b7cbaa766d0

commit 04652db4dfdd8c3663b50371a5f36b7cbaa766d0
Author: Steven Holte <holte@google.com>
Date: Tue Aug 22 22:29:09 2017

Convert ResourceCoordinator to NavigationId UKMs

Bug: 754895
Change-Id: I9a7d8b8021e942e8ed3ae90f3dae5d640768bfd6
Reviewed-on: https://chromium-review.googlesource.com/614907
Commit-Queue: Steven Holte <holte@chromium.org>
Reviewed-by: Oystein Eftevaag <oysteine@chromium.org>
Cr-Commit-Position: refs/heads/master@{#496475}
[modify] https://crrev.com/04652db4dfdd8c3663b50371a5f36b7cbaa766d0/chrome/browser/metrics/process_memory_metrics_emitter_browsertest.cc
[modify] https://crrev.com/04652db4dfdd8c3663b50371a5f36b7cbaa766d0/chrome/browser/resource_coordinator/resource_coordinator_web_contents_observer.cc
[modify] https://crrev.com/04652db4dfdd8c3663b50371a5f36b7cbaa766d0/chrome/browser/resource_coordinator/resource_coordinator_web_contents_observer.h
[modify] https://crrev.com/04652db4dfdd8c3663b50371a5f36b7cbaa766d0/services/metrics/public/cpp/ukm_source_id.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f0f467721dedbf23f30da83f3e6c70439b6b07e4

commit f0f467721dedbf23f30da83f3e6c70439b6b07e4
Author: Steven Holte <holte@google.com>
Date: Mon Dec 11 20:54:51 2017

Migrate Flash UKM to shared SourceId

Bug: 754895
Change-Id: I7b25e9759cc350b15581c1cf197ba1e534e11b55
Reviewed-on: https://chromium-review.googlesource.com/815765
Reviewed-by: Tommy Li <tommycli@chromium.org>
Commit-Queue: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523201}
[modify] https://crrev.com/f0f467721dedbf23f30da83f3e6c70439b6b07e4/chrome/browser/plugins/plugin_info_host_impl.cc
[modify] https://crrev.com/f0f467721dedbf23f30da83f3e6c70439b6b07e4/chrome/browser/plugins/plugin_info_host_impl.h

Summarizing the remaining work to avoid usage of UpdateSourceURL:

Cases which should be simple migrations:
cc/trees/ukm_manager.cc
https://bugs.chromium.org/p/chromium/issues/detail?id=892361

third_party/blink/renderer/modules/vr/navigator_vr.cc
https://bugs.chromium.org/p/chromium/issues/detail?id=892358

third_party/blink/renderer/core/dom/document.cc
 - This should be redundant with data from DocumentCreated links.
   We should update analysis to use those links and remove this.

components/translate/core/browser/translate_ranker_impl.cc

Odd cases:
chrome/browser/media/media_engagement_session.cc
 - This uses SourceId for a "Media session" which has data for multiple
   navigations with the same origin, so we should replace this with some link to
   those navigations.

chrome/browser/notifications/platform_notification_service_impl.cc
 - These aren't always associated with a pageload in the same session,
   so they are a special case.
components/offline_pages/core/offline_pages_ukm_reporter.cc