Implement important sites dialog for desktop.

chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.js

Index: chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.js
diff --git a/chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.js b/chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.js
index 5c8d55722aeff98d7b8e3bde1df11083fb4a7bb0..ad69488bc3c84bd0566f8df8e7b1cfe56baa53be 100644
--- a/chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.js
+++ b/chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.js
@@ -21,6 +21,15 @@ Polymer({
     },
 
     /**
+     * State of this dialog, either "clearBrowsingData" or "importantSites".
+     * @private
+     */
+    dialogState_: {
+      type: String,
+      value: 'clearBrowsingData',
+    },
+
+    /**
      * Results of browsing data counters, keyed by the suffix of
      * the corresponding data type deletion preference, as reported
      * by the C++ side.
@@ -28,9 +37,8 @@ Polymer({
      */
     counters_: {
       type: Object,
-      value: {
-        // Will be filled as results are reported.
-      }
+      // Will be filled as results are reported.
+      value: function() { return {}; }
     },
 
     /**
@@ -60,6 +68,19 @@ Polymer({
       type: Boolean,
       value: false,
     },
+
+    /** @private {!Array<ImportantSite>} */
+    importantSites_: {
+      type: Array,
+      value: function() { return []; }
+    },
+
+    /** @private */
+    importantSitesFlagEnabled_: {
+      type: Boolean,
+      value: false,
+    },
+
   },
 
   /** @private {settings.ClearBrowsingDataBrowserProxy} */
@@ -80,9 +101,21 @@ Polymer({
   attached: function() {
     this.browserProxy_ =
         settings.ClearBrowsingDataBrowserProxyImpl.getInstance();
-    this.browserProxy_.initialize().then(function() {
-      this.$.dialog.showModal();
-    }.bind(this));
+    this.browserProxy_.initialize()
+        .then(function() {
+          this.$.dialog.showModal();
+          return this.browserProxy_.fetchImportantSites();
+        }.bind(this))
+        .then(this.receiveImportantSites.bind(this));
+  },
+
+  /**
+   * @param {!ImportantSitesResponse} result
+   * @private
+   */
+  receiveImportantSites: function(result) {
+    this.importantSitesFlagEnabled_ = result.flagEnabled;
+    this.set('importantSites_', result.importantSites);
   },
 
   /**
@@ -114,24 +147,65 @@ Polymer({
   },
 
   /**
+   * @param {string} currentDialogState The current dialog state.
+   * @return {boolean} Whether this is the clear browsing data dialog.
+   * @private
+   */
+  isClearBrowsingDataDialog_: function(currentDialogState) {
+    return currentDialogState == 'clearBrowsingData';
+  },
+
+  /**
+   * @param {string} currentDialogState The current dialog state.
+   * @return {boolean} Whether this is the important sites dialog.
+   * @private
+   */
+  isImportantSitesDialog_: function(currentDialogState) {
+    return currentDialogState == 'importantSites';
+  },
+
+  /** @private */
+  shouldShowImportantSites_: function() {
+    if (this.isImportantSitesDialog_(this.dialogState_))
+      return false;
+    if (!this.importantSitesFlagEnabled_)
+      return false;
+    if (!this.$.cookiesCheckbox.checked && !this.$.cacheCheckbox.checked) {
+      return false;
+    }
+    var haveImportantSites = this.importantSites_.length > 0;
+    chrome.send(
+        'metricsHandler:recordBooleanHistogram',
+        ['History.ClearBrowsingData.ImportantDialogShown', haveImportantSites]);
+    return haveImportantSites;
+  },
+
+  /**
    * Handles the tap on the Clear Data button.
    * @private
    */
   onClearBrowsingDataTap_: function() {
+    if (this.shouldShowImportantSites_()) {
+      this.dialogState_ = 'importantSites';
+      return;
+    }
+
     this.clearingInProgress_ = true;
 
-    this.browserProxy_.clearBrowsingData().then(
-      /**
-       * @param {boolean} shouldShowNotice Whether we should show the notice
-       *     about other forms of browsing history before closing the dialog.
-       */
-      function(shouldShowNotice) {
-        this.clearingInProgress_ = false;
-        this.showHistoryDeletionDialog_ = shouldShowNotice;
-
-        if (!shouldShowNotice)
-          this.$.dialog.close();
-      }.bind(this));
+    this.browserProxy_.clearBrowsingData(this.importantSites_)
+        .then(
+            /**
+             * @param {boolean} shouldShowNotice Whether we should show the
+             * notice about other forms of browsing history before closing the
+             * dialog.
+             */
+            function(shouldShowNotice) {
+              this.clearingInProgress_ = false;
+              this.showHistoryDeletionDialog_ = shouldShowNotice;
+
+              if (!shouldShowNotice)
+                this.$.dialog.close();
+            }.bind(this));
   },
 
   /** @private */