Allow Observatory debugger to switch isolates.

runtime/observatory/lib/src/app/page.dart

 // Copyright (c) 2014, 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.
 
 part of app;
 
 /// A [Page] controls the user interface of Observatory. At any given time
 /// one page will be the current page. Pages are registered at startup.
 /// When the user navigates within the application, each page is asked if it
 /// can handle the current location, the first page to say yes, wins.
@@ skipping 40 matching lines @@
       element = new Element.tag(elementTagName);
     }
   }
 
   void _visit(Uri uri) {
     assert(uri != null);
     assert(canVisit(uri));
   }
 
   Future<Isolate> getIsolate(Uri uri) {
-    return app.vm.getIsolate(uri.queryParameters['isolateId']).catchError((e) {
-      Logger.root.severe('$path visit error: $e');
-      return e;
-    });
+    return app.vm.getIsolate(uri.queryParameters['isolateId'])
+      .catchError((e, stack) {
+        Logger.root.severe('$path visit error: $e\n$stack');
+        return e;
+      });
   }
 
   bool canVisit(Uri uri) => uri.path == path;
 }
 
 /// Error page for unrecognized paths.
 class ErrorPage extends Page {
   ErrorPage(app) : super(app);
 
   void onInstall() {
@@ skipping 28 matching lines @@
 class VMPage extends SimplePage {
   VMPage(app) : super('vm', 'service-view', app);
 
   void _visit(Uri uri) {
     super._visit(uri);
     app.vm.reload().then((vm) {
       if (element != null) {
         ServiceObjectViewElement serviceElement = element;
         serviceElement.object = vm;
       }
-    }).catchError((e) {
-      Logger.root.severe('VMPage visit error: $e');
+    }).catchError((e, stack) {
+      Logger.root.severe('VMPage visit error: $e\n$stack');
     });
   }
 }
 
 class FlagsPage extends SimplePage {
   FlagsPage(app) : super('flags', 'flag-list', app);
 
   void _visit(Uri uri) {
     super._visit(uri);
     app.vm.getFlagList().then((flags) {
       if (element != null) {
         FlagListElement serviceElement = element;
         serviceElement.flagList = flags;
       }
-    }).catchError((e) {
-      Logger.root.severe('FlagsPage visit error: $e');
+    }).catchError((e, stack) {
+      Logger.root.severe('FlagsPage visit error: $e\n$stack');
     });
   }
 }
 
 class InspectPage extends SimplePage {
   InspectPage(app) : super('inspect', 'service-view', app);
 
   void _visit(Uri uri) {
     super._visit(uri);
     getIsolate(uri).then((isolate) {
@@ skipping 33 matching lines @@
 
 class DebuggerPage extends SimplePage {
   DebuggerPage(app) : super('debugger', 'debugger-page', app);
 
   void _visit(Uri uri) {
     super._visit(uri);
     getIsolate(uri).then((isolate) {
       if (element != null) {
         /// Update the page.
         DebuggerPageElement page = element;
+        page.app = app;
         page.isolate = isolate;
       }
     });
   }
 }
 
 class CpuProfilerPage extends SimplePage {
   CpuProfilerPage(app) : super('profiler', 'cpu-profile', app);
 
   void _visit(Uri uri) {
@@ skipping 129 matching lines @@
   void _visit(Uri uri) {
     assert(element != null);
     assert(canVisit(uri));
     app.vm.getIsolate(uri.queryParameters['isolateId']).then((i) {
       (element as MetricsPageElement).isolate = i;
     });
   }
 
   bool canVisit(Uri uri) => uri.path == 'metrics';
 }