Teach the Observatory about Contexts. Factor out object graph information from the instance view.

Address various issues with mismatched tags and type errors.

R=johnmccutchan@google.com

Review URL: https://codereview.chromium.org//532063002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@39845 260f80e4-7a28-3924-810f-c04153c831b5
Fix scheme's toLowerCase detection.

BUG=
R=lrn@google.com

Review URL: https://codereview.chromium.org//532273002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@39846 260f80e4-7a28-3924-810f-c04153c831b5
Cleanup resource loading of the VM.

There is not only one path for loading resources, and it's async.

BUG=

Review URL: https://codereview.chromium.org//529203004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@39847 260f80e4-7a28-3924-810f-c04153c831b5
Reuse HttpClient in the built-in resource loader.

BUG=

Review URL: https://codereview.chromium.org//539473002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@39848 260f80e4-7a28-3924-810f-c04153c831b5
Fix handling of Windows paths after cleanup.

BUG=

Review URL: https://codereview.chromium.org//539863002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@39849 260f80e4-7a28-3924-810f-c04153c831b5
Mark observatory tests as failing on the analyzer

Filed issue 20805

Review URL: https://codereview.chromium.org//537853002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@39850 260f80e4-7a28-3924-810f-c04153c831b5
Mark  isolate/compile_time_error_test/none slow on mobile safari

Review URL: https://codereview.chromium.org//544543002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@39851 260f80e4-7a28-3924-810f-c04153c831b5