MD History: Implement search functionality.

chrome/browser/resources/md_history/history_item.js

Index: chrome/browser/resources/md_history/history_item.js
diff --git a/chrome/browser/resources/md_history/history_item.js b/chrome/browser/resources/md_history/history_item.js
index 4b988cd6437cc1bde1cccea3e4f79947977d9da0..aa27c63214d38e4fd4d11e32862016f1b03beed0 100644
--- a/chrome/browser/resources/md_history/history_item.js
+++ b/chrome/browser/resources/md_history/history_item.js
@@ -13,7 +13,8 @@ Polymer({
 
     websiteTitle_: {
       type: String,
-      value: ''
+      value: '',
+      observer: 'setSearchedTextToBold_'
     },
 
     // Domain is the website text shown on the history-item next to the title.
@@ -47,6 +48,13 @@ Polymer({
       value: 0
     },
 
+    // Search term used in the chrome.send to obtain this history-item.
+    searchTerm: {
+      type: String,
+      value: '',
+      observer: 'setSearchedTextToBold_'
+    },
+
     selected: {
       type: Boolean,
       value: false,
@@ -92,6 +100,48 @@ Polymer({
     e.stopPropagation();
   },
 
+  /**
+   * If the results shown are search results set the search term to be bold
+   * where it is displayed in the history-item title.
+   * @private
+   */
+  setSearchedTextToBold_: function() {
+    var i = 0;
+    var title = this.$.title;
+
+    if (this.searchTerm == '' || this.searchTerm == null) {
+      title.textContent = this.websiteTitle_;
+      return;
+    }
+
+    var re = new RegExp(this.quoteString_(this.searchTerm), 'gim');
+    var match;
+    title.textContent = '';
+    while (match = re.exec(this.websiteTitle_)) {
+      if (match.index > i)
+        title.appendChild(document.createTextNode(
+            this.websiteTitle_.slice(i, match.index)));
+      i = re.lastIndex;
+      // Mark the highlighted text in bold.
+      var b = document.createElement('b');
+      b.textContent = this.websiteTitle_.substring(match.index, i);
+      title.appendChild(b);
+    }
+    if (i < this.websiteTitle_.length)
+      title.appendChild(document.createTextNode(this.websiteTitle_.slice(i)));
+  },
+
+  /**
+   * Quote a string so it can be used in a regular expression.
+   * @param {string} searchTerm The source string.
+   * @return {string} The escaped string.
+   * @private
+   */
+  quoteString_: function(searchTerm) {
+    return searchTerm.replace(/([\\\.\+\*\?\[\^\]\$\(\)\{\}\=\!\<\>\|\:])/g,
+        '\\$1');
+  },
+
   selectionNotAllowed_: function() {
     return !loadTimeData.getBoolean('allowDeletingHistory');
   }