Use server.getContainingContext() in execution domain.

pkg/analysis_server/lib/src/domain_execution.dart

Index: pkg/analysis_server/lib/src/domain_execution.dart
diff --git a/pkg/analysis_server/lib/src/domain_execution.dart b/pkg/analysis_server/lib/src/domain_execution.dart
index 59d70afbfc23f474508e4d3749fc84364f7cf863..145f1ba8fb64e77806916bd3e840edadd7b1ff47 100644
--- a/pkg/analysis_server/lib/src/domain_execution.dart
+++ b/pkg/analysis_server/lib/src/domain_execution.dart
@@ -96,7 +96,7 @@ class ExecutionDomainHandler implements RequestHandler {
       return new Response.invalidParameter(request, 'id',
           'There is no execution context with an id of $contextId');
     }
-    AnalysisContext context = server.getAnalysisContext(path);
+    AnalysisContext context = server.getContainingContext(path);

[Brian Wilkerson, 2015/05/04 20:06:19]

Why do we have both methods? They appear to be doing the same thing but in
different ways.

[scheglov, 2015/05/04 20:15:22]

Mostly for external files.
For example when we get a file from the Pub cache, we want to find it in an
AnalysisContext, even if it is not in an analysis root.

I think we don't need this for the execution domain.

     if (context == null) {
       return new Response.invalidExecutionContext(request, contextId);
     }