Gitiles needs a git search feature.

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Visit chromium.googlesource.com/chromium/src
2. Try to find a recent change. That is difficult without a git search feature.

What is the expected output? What do you see instead?
Gitiles should provide a git search feature. However, Gitiles does not provide 
search.

What version of the product are you using? On what operating system?
Whichever version used by chromium.googlesource.com
Windows 8.1 (6.3)

Please provide any additional information below.
(Trying to contribute to the Chromium project)

Original issue reported on code.google.com by msimprov...@gmail.com on 8 Apr 2015 at 1:22