Updating to commit 0e0e5b7254e076a62326ab7305ba49e8515f0c91
from github.com/google/pprof

Recent modifications to the vendored pprof, such as skipping
TestWebInterface to avoid starting a web browser, have all been fixed
upstream.

Change-Id: I72e11108c438e1573bf2f9216e76d157378e8d45
Reviewed-on: https://go-review.googlesource.com/93375
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>