vm/service/observatory: Add coverage for functions, some tests, and fix buggy filter

runtime/vm/coverage.cc

Index: runtime/vm/coverage.cc
diff --git a/runtime/vm/coverage.cc b/runtime/vm/coverage.cc
index ed72bb0aaaabe0f595b7ccfcff5d08a757e60299..1ed5e1e263fd510f5c34844f9e628cffd4c550bb 100644
--- a/runtime/vm/coverage.cc
+++ b/runtime/vm/coverage.cc
@@ -179,6 +179,10 @@ void CodeCoverage::PrintClass(const Library& lib,
         pos_to_line.Clear();
         break;
       }
+      if (!filter->ShouldOutputCoverageFor(lib, saved_url, cls, function)) {

[Michael Lippautz (Google), 2014/07/09 23:49:21]

We also need to filter within the second loop (that continues looping over
functions in the same source file).

Double-loop is unfortunate, but necessary (?) because of ValueObjects.

[Cutch, 2014/07/10 20:21:06]

Acknowledged.

+        i++;
+        continue;
+      }
       CompileAndAdd(function, hits_arr, pos_to_line);
       if (function.HasImplicitClosureFunction()) {
         function = function.ImplicitClosureFunction();