Add Timeline Developer Profiles for faster category switching

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

 // Copyright (c) 2015, 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 timeline_page_element;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:html';
 import 'observatory_element.dart';
@@ skipping 79 matching lines @@
     return label;
   }
 
   void _refreshRecorderUI() {
     DivElement e = $['streamList'];
     e.children.clear();
 
     for (String streamName in _availableStreams) {
       e.children.add(_makeStreamToggle(streamName));
     }
+
+    streamPresetSelector = streamPresetFromRecordedStreams();
+  }
+
+  // Dart developers care about the following streams:
+  List<String> _dartPreset =
+      ['GC', 'Compiler', 'Dart'];
+
+  // VM developers care about the following streams:
+  List<String> _vmPreset =
+      ['GC', 'Compiler', 'Dart', 'Debugger', 'Embedder', 'Isolate', 'VM'];
+
+  String streamPresetFromRecordedStreams() {
+    if (_availableStreams.length == 0) {
+      return 'None';
+    }
+    if (_recordedStreams.length == 0) {
+      return 'None';
+    }
+    if (_recordedStreams.length == _availableStreams.length) {
+      return 'All';
+    }
+    if ((_vmPreset.length == _recordedStreams.length) &&
+        _recordedStreams.containsAll(_vmPreset)) {
+      return 'VM';
+    }
+    if ((_dartPreset.length == _recordedStreams.length) &&
+        _recordedStreams.containsAll(_dartPreset)) {
+      return 'Dart';
+    }
+    return 'Custom';
+  }
+
+  void _applyPreset() {
+    switch (streamPresetSelector) {
+      case 'None':
+        _recordedStreams.clear();
+        break;
+      case 'All':
+        _recordedStreams.clear();
+        _recordedStreams.addAll(_availableStreams);
+        break;
+      case 'VM':
+        _recordedStreams.clear();
+        _recordedStreams.addAll(_vmPreset);
+        break;
+      case 'Dart':
+        _recordedStreams.clear();
+        _recordedStreams.addAll(_dartPreset);
+        break;
+      case 'Custom':
+        return;
+    }
+    _applyStreamChanges();
+    _updateRecorderUI();
   }
 
   Future _updateRecorderUI() async {
     // Grab the current timeline flags.
     ServiceMap response = await app.vm.invokeRpc('_getVMTimelineFlags', {});
     assert(response['type'] == 'TimelineFlags');
     // Process them so we know available streams.
     _processFlags(response);
     // Refresh the UI.
     _refreshRecorderUI();
   }
 
   Future _setupInitialState() async {
     await _updateRecorderUI();
+    SelectElement e = $['selectPreset'];
+    e.onChange.listen((_) {
+      _applyPreset();
+    });
     // Finally, trigger a reload so we start with the latest timeline.
     await refresh();
   }
 
   Future refresh() async {
     await app.vm.reload();
     await app.vm.reloadIsolates();
     return postMessage('refresh');
   }
 
@@ skipping 16 matching lines @@
     final top = e.offset.top;
     final bottomMargin = 32;
     final mainHeight = totalHeight - top - bottomMargin;
     e.style.setProperty('height', '${mainHeight}px');
     e.style.setProperty('width', '100%');
   }
 
 
   StreamSubscription _resizeSubscription;
   @observable String recorderName;
+  @observable String streamPresetSelector = 'None';
   final Set<String> _availableStreams = new Set<String>();
   final Set<String> _recordedStreams = new Set<String>();
 }