Add support for Java nano protocol buffers for Android (take 2).

Add support for Java nano protocol buffers for Android (take 2).

This CL adds a new dependency on the protocol buffer compiler
from the android source tree, since this compiler supports
generating Java files using the nano runtime.

The initial version of this dependency is 2.2.0a, but checked
out as what the Android 4.4.4 Release 2.0.1 tag points to.

This CL adds a new protoc binary (for compiling protos) that supports
this, and also adds a Java library with the runtime.

To simplify use of this, it also updates build/protoc_java.gypi to
support generating nano protos by specifying an optional
proto_runtime argument. The argument defaults to 'lite' which does
the same thing as before this change, and setting it to 'nano'
generates the new style Java files.

The plan is to quickly deprecate the 'lite' runtime for Java, since
it is too big and uses too many methods.

TBR=darin@chromium.org,cjhopman@chromium.org
BUG=377891, 410067
Committed: https://crrev.com/38f28ba65426989765f8d070ef5f64b5fbce23fa
Cr-Commit-Position: refs/heads/master@{#293236}

[nyquist, 2014-09-03 20:52:57]

nyquist@chromium.org changed reviewers:
+ cjhopman@chromium.org, darin@chromium.org

[nyquist, 2014-09-03 20:52:58]

TBRin darin and cjhopman.

Patch set 1 is original patch.
Patch set 2 is the diff (changing repository).

[nyquist, 2014-09-03 21:00:55]

The CQ bit was checked by nyquist@chromium.org

[commit-bot: I haz the power, 2014-09-03 21:01:13]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/nyquist@chromium.org/532303003/20001

[cjhopman, 2014-09-03 21:14:17]

lgtm

[commit-bot: I haz the power, 2014-09-04 00:29:40]

Committed patchset #2 (id:20001) as a94f6dad963342ac1ec13f6c317e0810ce0ddfe2

[commit-bot: I haz the power, 2014-09-10 03:29:02]

Patchset 2 (id:??) landed as
https://crrev.com/38f28ba65426989765f8d070ef5f64b5fbce23fa
Cr-Commit-Position: refs/heads/master@{#293236}

[Lei Zhang, 2014-09-23 21:42:57]

https://codereview.chromium.org/532303003/diff/20001/third_party/android_prot...
File third_party/android_protobuf/README.chromium (right):

https://codereview.chromium.org/532303003/diff/20001/third_party/android_prot...
third_party/android_protobuf/README.chromium:10: Name:
It's weird to have 2 set of entries in the same README.chromium file.
tools/licenses.py doesn't understand this and will only pick up the first entry
and put it in about:credits.