The warnings and warnings-as-errors are enabled by set chromium_code to
1. Chromium build disables warnings and warnings-as-errors by default
on external contents.
And fix the errors with them enabled. Mostly defined but not used,
sign-unsign comparison, unsigned string formatting, and return value not
used etc.
Change-Id: I305b63924955a84172e98e0ebfe5aba0f11bdb37
BoxBuffer wraps either BoxReader for reading or BufferWriter for writing.
Thus it is capable of doing either reading or writing, but not both.
Change-Id: Id57370755a586bfdef1291a23af29f5b1feec903
Kongqun Yang