Show dartdoc for completion elements.

R=brianwilkerson@google.com, danrubel@google.com
BUG=

Review URL: https://codereview.chromium.org//788803002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@42213 260f80e4-7a28-3924-810f-c04153c831b5
Minor optimization in _GrowableList.removeAt.

BUG=
R=srdjan@google.com

Review URL: https://codereview.chromium.org//790873002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@42214 260f80e4-7a28-3924-810f-c04153c831b5
Complete and clean up breakpoint support in all 3 debuggers embedded in MIPS,
ARM, and ARM64 simulators.
Implement the same debugging commands in all 3 simulators: stop_sim_at flag, bt,
p icount, break, del, unstop, etc...

R=zra@google.com

Review URL: https://codereview.chromium.org//789903002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@42216 260f80e4-7a28-3924-810f-c04153c831b5
Make completion tests handle exceptions during getSuggestions().

Previously, if an exception occurred during getSuggestions(), or the
future returned by it completed with an error, the completion test
would exit without calling tearDown().

R=brianwilkerson@google.com

Review URL: https://codereview.chromium.org//787863003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@42217 260f80e4-7a28-3924-810f-c04153c831b5
Hooks for instrumentation

R=scheglov@google.com

Review URL: https://codereview.chromium.org//787763004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@42218 260f80e4-7a28-3924-810f-c04153c831b5