There are multiple places call g_browser_process->data_use_measurement::ChromeDataUseMeasurement(), so can we make ChromeDataUseMeasurement as a global variable too? Like  network::NetworkConnectionTracker in NetworkServiceInstance:
https://cs.chromium.org/chromium/src/content/browser/network_service_instance.cc?rcl=914a6f6170b45fdcb5254ec4c94915d8b3c410db&l=39

Alternatively, we could let ChromeContentBrowserClient own it, create it during earlier startup, and plumb its pointer through BrowserMainParts to the BrowserProcessImpl. Similar to what we did for ChromeFeatureListCreator, just lots of plumbing. 

i have a fix here: https://chromium-review.googlesource.com/c/chromium/src/+/1303180

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cafb27b389ecebb9e35851d957679954c003c25c

commit cafb27b389ecebb9e35851d957679954c003c25c
Author: Min Qin <qinmin@chromium.org>
Date: Tue Oct 30 18:02:03 2018

make a singleton ChromeDataUseMeasurement for network service

When network service is enabled, it is possible for ServiceManager
to launch network service without the browser process. This will cause
a crash in ChromeContentBrowserClient::OnNetworkServiceDataUseUpdate().
This CL fixes the issue by making ChromeDataUsemeasurement a singleton
for network service. Also it fixes a bunch of BrowserThread checks
as BrowserThread will not be available when browser process isn't created.

BUG= 898970 

Change-Id: I8638239c62a852374f52d5832d86558f4c4bef19
Reviewed-on: https://chromium-review.googlesource.com/c/1303180
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: rajendrant <rajendrant@chromium.org>
Commit-Queue: Min Qin <qinmin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#603960}
[modify] https://crrev.com/cafb27b389ecebb9e35851d957679954c003c25c/chrome/browser/browser_process.h
[modify] https://crrev.com/cafb27b389ecebb9e35851d957679954c003c25c/chrome/browser/browser_process_impl.cc
[modify] https://crrev.com/cafb27b389ecebb9e35851d957679954c003c25c/chrome/browser/browser_process_impl.h
[modify] https://crrev.com/cafb27b389ecebb9e35851d957679954c003c25c/chrome/browser/chrome_content_browser_client.cc
[modify] https://crrev.com/cafb27b389ecebb9e35851d957679954c003c25c/chrome/browser/data_use_measurement/chrome_data_use_measurement.cc
[modify] https://crrev.com/cafb27b389ecebb9e35851d957679954c003c25c/chrome/browser/data_use_measurement/chrome_data_use_measurement.h
[modify] https://crrev.com/cafb27b389ecebb9e35851d957679954c003c25c/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc
[modify] https://crrev.com/cafb27b389ecebb9e35851d957679954c003c25c/chrome/test/base/testing_browser_process.cc
[modify] https://crrev.com/cafb27b389ecebb9e35851d957679954c003c25c/chrome/test/base/testing_browser_process.h