[observatory] Fix/workaround a few crashes

TEST=N/A

Change-Id: I992acd131cee6473827d3a4306c37678cbe55d2b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/229966
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>

Author: jensjoha

runtime/observatory/lib/src/elements/debugger.dart

@@ -2545,7 +2545,7 @@ class DebuggerFrameElement extends CustomElement implements Renderable {
     if (_expanded) {
       final homeMethod = _frame.function!.homeMethod;
       String? homeMethodName;
-      if ((homeMethod.dartOwner is S.Class) && homeMethod.isStatic!) {
+      if ((homeMethod.dartOwner is S.Class) && homeMethod.isStatic == true) {
         homeMethodName = '<class>';
       } else if (homeMethod.dartOwner is S.Library) {
         homeMethodName = '<library>';

runtime/observatory/lib/src/service/object.dart

@@ -3098,7 +3098,11 @@ class Context extends HeapObject implements M.Context {
     } else {
       var localVariables = <ContextElement>[];
       for (var element in map['variables']) {
-        localVariables.add(new ContextElement(element));
+        try {
+          localVariables.add(new ContextElement(element));
+        } catch (e) {
+          // Swallowing '$e' to still show stuff...
+        }
       }
       variables = localVariables;
     }