DevTools: implement release note behind an experiment

third_party/WebKit/Source/devtools/front_end/console/ConsoleView.js

Index: third_party/WebKit/Source/devtools/front_end/console/ConsoleView.js
diff --git a/third_party/WebKit/Source/devtools/front_end/console/ConsoleView.js b/third_party/WebKit/Source/devtools/front_end/console/ConsoleView.js
index c39376afb17fa19833210c899a4afe3e55bc84c0..704eba8fed00088f4dfc4e441901af6d058a439c 100644
--- a/third_party/WebKit/Source/devtools/front_end/console/ConsoleView.js
+++ b/third_party/WebKit/Source/devtools/front_end/console/ConsoleView.js
@@ -37,6 +37,7 @@ Console.ConsoleView = class extends UI.VBox {
     super();
     this.setMinimumSize(0, 35);
     this.registerRequiredCSS('console/consoleView.css');
+    this.registerRequiredCSS('console/releaseNoteMessage.css');

[luoe, 2017/02/11 00:30:54]

Could we move releaseNoteMessage.css into the help module?

 
     this._searchableView = new UI.SearchableView(this);
     this._searchableView.setPlaceholder(Common.UIString('Find string in logs'));
@@ -134,6 +135,10 @@ Console.ConsoleView = class extends UI.VBox {
 
     /** @type {!Array.<!Console.ConsoleViewMessage>} */
     this._consoleMessages = [];
+
+    this._releaseNoteManager = new Help.ReleaseNoteManager();
+    if (!Host.isUnderTest())
+      this._addReleaseNote();
     this._viewMessageSymbol = Symbol('viewMessage');
 
     this._consoleHistorySetting = Common.settings.createLocalSetting('consoleHistory', []);
@@ -188,6 +193,29 @@ Console.ConsoleView = class extends UI.VBox {
     return this._searchableView;
   }
 
+  /**
+   * @param {number} version
+   */
+  removeReleaseNote(version) {
+    this._consoleMessages = this._consoleMessages.filter(
+        message => message.consoleMessage().level !== SDK.ConsoleMessage.MessageLevel.Note);
+    this._releaseNoteManager.sawReleaseNote(version);
+    this._updateMessageList();
+  }
+
+  /**
+   * @param {number} version
+   */
+  sawReleaseNote(version) {
+    this._releaseNoteManager.sawReleaseNote(version);
+  }
+
+  _addReleaseNote() {
+    var releaseNote = this._releaseNoteManager.maybeGetReleaseNote();
+    if (releaseNote)
+      this._addConsoleMessage(releaseNote);
+  }
+
   _clearHistory() {
     this._consoleHistorySetting.set([]);
     this._prompt.history().setHistoryData([]);