Now breaks down to the line level, and shows an annotated display
of the source file with the size cost of each line, as well as all
symbols that contribute to that size (can be many in the case of
templates).

Example output here:

https://dl.dropboxusercontent.com/u/116514/chrome.dll.html
https://dl.dropboxusercontent.com/u/116514/chrome_child.dll.html

Not really intended for loading remotely as they're very large,
but might eventually finish loading.

R=jam@chromium.org, mkosiba@chromium.org
BUG=441867

Review URL: https://codereview.chromium.org/801123002

Cr-Commit-Position: refs/heads/master@{#308394}