There doesn't appear to have been any affect on release binaries with the exception of MIPS, and I doubt there are any MIPS users.

I started https://codereview.chromium.org/2861153002/. I will send it out for review after I make sure things are still building.

Re #2. While this only has an effect on MIPS release build, I think we should fix it because Cronet consumers do use our debug builds (which increased in size across the board).

How big the increase on non-MIPS release binaries? 

No observed effect on non-MIPS release binaries.

I wonder if dead code stripping is enabled for non-MIPS builds that's making only mips get the increase? If so, maybe it should be enabled for mips as well?

Re #6. It might be. Pauljensen@ started a thread to remove MIPS support, so hopefully we won't need to deal with it soon.  
Our embedders do ship with Cronet debug builds to early testers. If we want to have a reasonable sized debug builds, we should fix it even if this only affects debug. Given that fixing the problem seems trivial (https://codereview.chromium.org/2861153002/), let's just fix it.

sgtm

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a59254424997b8dc543d3d2a3315f707d5c07c79

commit a59254424997b8dc543d3d2a3315f707d5c07c79
Author: xunjieli <xunjieli@chromium.org>
Date: Mon May 08 20:01:44 2017

Make single_sample_metrics into its own target

This CL makes single_sample_metrics into its own target so consumers who depend
on components/metrics can avoid pulling in the dependency if desired.

crrev.com/2687583002 increased cronet debug binary size by 40% (3.5MB) and
release binary size by 4% (300KB). The effect is not seen on all architectures,
but we should try to limit the impact.

BUG= 718833 

Review-Url: https://codereview.chromium.org/2861153002
Cr-Commit-Position: refs/heads/master@{#470094}

[modify] https://crrev.com/a59254424997b8dc543d3d2a3315f707d5c07c79/components/metrics/BUILD.gn
[modify] https://crrev.com/a59254424997b8dc543d3d2a3315f707d5c07c79/content/browser/BUILD.gn
[modify] https://crrev.com/a59254424997b8dc543d3d2a3315f707d5c07c79/content/browser/DEPS
[modify] https://crrev.com/a59254424997b8dc543d3d2a3315f707d5c07c79/content/renderer/BUILD.gn
[modify] https://crrev.com/a59254424997b8dc543d3d2a3315f707d5c07c79/content/renderer/DEPS