Added kUnboundedSize to SizeLimitedQuarantine

Added kUnboundedSize (~0) to specify unlimited capacity instead of using 0.
Trimming a quarantine with max size 0 should flush it.
BUG=
R=chrisha@chromium.org

Committed: https://code.google.com/p/sawbuck/source/detail?r=2287

[peterssen, 2014-08-28 21:28:28]

PTAL. I'll cleanup existing code (BlockHeapManager) later.

[chrisha, 2014-08-29 13:17:23]

Nice!

https://codereview.appspot.com/139830043/diff/1/syzygy/agent/asan/quarantines...
File syzygy/agent/asan/quarantines/size_limited_quarantine.h (right):

https://codereview.appspot.com/139830043/diff/1/syzygy/agent/asan/quarantines...
syzygy/agent/asan/quarantines/size_limited_quarantine.h:54: static const size_t
UNBOUNDED_MAX_SIZE = ~0;
More often than not we tend to use kConstantVariable notation. Also, the 'max'
is redundant here. Maybe call this kUnboundedSize?

And if we're going to change the semantics for max_quarantine_size_ can we also
change them for max_object_size_, to be consistent?

[peterssen, 2014-08-29 17:07:50]

PTAL. Now kUnboundedSize can be use for max_object_size too.

[chrisha, 2014-08-29 17:37:29]

lgtm with nits

https://codereview.appspot.com/139830043/diff/20001/syzygy/agent/asan/quarant...
File syzygy/agent/asan/quarantines/size_limited_quarantine.h (right):

https://codereview.appspot.com/139830043/diff/20001/syzygy/agent/asan/quarant...
syzygy/agent/asan/quarantines/size_limited_quarantine.h:83: //     quarantine.
Use UNBOUNDED_MAX_SIZE for unlimited (no max).
Fix this comment.

https://codereview.appspot.com/139830043/diff/20001/syzygy/agent/asan/quarant...
syzygy/agent/asan/quarantines/size_limited_quarantine.h:91: //     Use
UNBOUNDED_MAX_SIZE for unlimited (no max).
Ditto.

[peterssen, 2014-08-29 19:12:23]

Committed patchset #4 (id:60001) manually as 2287 (presubmit successful).