Rework error handling in the service protocol and in Observatory.

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

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library script_inset_element;
 
 import 'dart:async';
 import 'dart:html';
 import 'observatory_element.dart';
 import 'service_ref.dart';
@@ skipping 141 matching lines @@
           r.append(cell(entry.count.toString()));
           r.append(cell(serviceRef(entry.target)));
           details.append(r);
         }
       }
       return details;
     });
   }
 }
 
-class DeclarationAnnotation extends Annotation {
+abstract class DeclarationAnnotation extends Annotation {
   DeclarationAnnotation(decl) {
     assert(decl.loaded);
     var script = decl.script;
     line = script.tokenToLine(decl.tokenPos);
     columnStart = script.tokenToCol(decl.tokenPos);
     if ((line == null) || (columnStart == null)) {
       line = 0;
       columnStart = 0;
       columnStop = 0;
     } else {
@@ skipping 448 matching lines @@
       e.classes.add("emptyBreakpoint");
       e.classes.add('noCopy');
       e.text = nbsp;
       return e;
     }
     e.text = 'B';
     update() {
       e.classes.clear();
       e.classes.add('noCopy');
 
-      if (busy) {
+      if (!line.possibleBpt) {
+        e.classes.add("emptyBreakpoint");
+        e.text = nbsp;
+      } else if (busy) {
         e.classes.add("busyBreakpoint");
       } else {
         if (line.breakpoints != null) {
           if (line.breakpointResolved) {
             e.classes.add("resolvedBreakpoint");
           } else {
             e.classes.add("unresolvedBreakpoint");
           }
         } else {
           e.classes.add("possibleBreakpoint");
         }
       }
     }
     line.changes.listen((_) => update());
     e.onClick.listen((event) {
       if (busy) {
         return;
       }
       busy = true;
       if (line.breakpoints == null) {
         // No breakpoint.  Add it.
-        line.script.isolate.addBreakpoint(line.script, line.line).then((_) {
-          busy = false;
-          update();
-        });
+        line.script.isolate.addBreakpoint(line.script, line.line)
+          .catchError((e, st) {
+            if (e is! ServerRpcException ||
+                (e as ServerRpcException).code !=
+                ServerRpcException.kNoBreakAtLine) {
+              app.handleException(e, st);
+            }})
+          .whenComplete(() {
+            busy = false;
+            update();
+          });
       } else {
         // Existing breakpoint.  Remove it.
         List pending = [];
         for (var bpt in line.breakpoints) {
           pending.add(line.script.isolate.removeBreakpoint(bpt));
         }
         Future.wait(pending).then((_) {
           busy = false;
           update();
         });
@@ skipping 61 matching lines @@
     e.append(span('\n'));
 
     return e;
   }
 
   ScriptInsetElement.created()
       : super.created() {
     _updateTask = new Task(update);
   }
 }