Add documentation on keeping code gender neutral.

styleguide/gender_neutral_code.md

+# Gender-neutral Chromium code
+
+## Why this is important
+
+Some points in our code, documentation and comments contain needless assumptions
+about the gender of a future reader, user, etc. __Example: "When the user logs
+into his profile."__
+
+Our [Code of Conduct](https://www.chromium.org/conduct) under "Be respectful and
+constructive" says:
+
+> Each of us has the right to __enjoy our experience__ and participate without
+> fear of harassment, __discrimination__, or __condescension__, whether blatant
+> or subtle.
+
+Emphasis is added: unnecessarily gendered code is discriminatory and
+condescending, and reading biased code isn't enjoyable.
+
+## Suggestions on how to keep code gender-neutral
+
+These are only suggestions. You make the call. 
+
+Things to avoid:
+
+* Gendered pronouns: he / she / him / her / his / hers, etc.
+* Instances of the phrases "he or she", "his/hers", "(s)he", etc. All of these
+  still exclude those who don't identify with either gender, and implicitly
+  (slightly) favor one gender via listing it first.
+* "Guys" as a gender-neutral term, which has male associations. Usually in
+  comments it implies anthropomorphism of inanimate objects and should be
+  replaced with a more precise technical term. If it does refer to people,
+  consider using "everyone", "folks", "people", "peeps", "y'all", etc.
+* Other gendered words: "brother", "mother", "man", etc.
+
+Cases that are likely fine to leave alone include:
+
+* References to a specific person ("Rachel is on leave; update this when she is
+  back.").
+* A name ("Guy" and "He" are both valid names).
+* A language code ("he" is the ISO 639-1 language code for Hebrew).
+* He as an abbreviation for "helium".
+* The Spanish word "he".
+* References to a specific fictional person ([Alice, Bob, ...](http://en.wikipedia.org/wiki/Alice_and_Bob)).
+  * For new code/comments, consider using just 'A', 'B' as names.
+* Quotations and content of things like public-domain books.
+* Partner agreements and legal documents we can no longer edit.
+* Occurrences in randomly generated strings or base-64 encodings.
+* Content in a language other than English unless you are fluent in that
+  language.
+
+How to change the remaining awkward intrusions of gender:
+
+* Try rewording things to not involve a pronoun at all. In many cases this makes
+  the documentation clearer. Example: "I tell him when I am all done." → "I tell
+  the owner when I am all done." This saves the reader a tiny bit of mental
+  pointer-dereferencing.
+* Try using [singular they](https://en.wikipedia.org/wiki/Singular_they).
+* Try making hypothetical people plural. "When the user is done he'll
+  probably..."
+→ "When users complete this step, they probably...".
+* When referring to a non-person, "it" or "one" may be good alternatives ([wikipedia link](http://wikipedia.org/wiki/Gender-specific_and_gender-neutral_pronouns#It_and_one_as_gender-neutral_pronouns)).
+
+## Example changelists
+
+For a long list of changes, see [this bug](https://crbug.com/542537). Some
+examples:
+
+* [Make some code gender neutral](https://crrev.com/e3496e19094cf7e711508fe69b197aa13725c790)
+* [Updates comments in the src files to remove gender specific terms](https://crrev.com/5b9d52e8a6ec9c11a675bae21c7d1b0448689fb6)
+* [Gender-neutralize a few more comments / strings](https://crrev.com/993006d919c7b0d3e2309041c1e45b8d7fc7ff0e)
+* [Make some android code gender neutral](https://crrev.com/93d83ac96c3d1c27be9ea7e842b25b3dded2550b)
+
+## Tools
+
+* [Here](https://cs.chromium.org/search/?q=%28%5E%7C%5Cs%7C%5C%28%7C%5C%5B%29%28%5BHh%5De%7C%5BSs%5Dhe%7C%5BHh%5Dis%7C%5BHh%5Ders?%7C%5BHh%5Dim%7C%5BHh%5Der%7C%5BGg%5Duys?%29%5Cb&sq=package:chromium&type=cs)
+  is a code search link prepopulated with a search that finds a lot of gendered
+  terms.
+* To search for files containing gendered terms, use this command (or a variant
+  of it):
+```
+git grep -wiEIl \ '(he)|(she)|(his)|(hers)|(him)|(her)|(guy)|(guys)'
+```
+* To search in a file open in vim for gendered terms, use this command:
+```
+/\<he\>\|\<she\>\|\<his\>\|\<hers\>\|\<him\>\|\<her\>\|\<guy\>\|\<guys\>|\<man\>\c
+```
+* There are presubmit checks available for this that are run for the infra and
+  v8 repos. They are not run for other repos as there are too many false
+  positives.
+
+## Thanks
+
+This document is based on an internal Google document by Rachel Grey and others,
+which can be found [here](https://goto.google.com/gender-neutral-code) (sorry,
+Googler only).