GitLab

This change adds a string `mime_type` to the list of fields in
SubresourceLoadInfo.  Notably, this is important for recording page
load metrics when the Network Service is enabled.

BUG=816684

Change-Id: Ie95bd46074f2a0f915eb8378800afa0f5ed46ecd
Reviewed-on: https://chromium-review.googlesource.com/963312Reviewed-by: Jay Civelli <jcivelli@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Conley Owens <cco3@chromium.org>
Cr-Commit-Position: refs/heads/master@{#545877}