Fixing iframe jank in the local omnibox popup.

chrome/browser/resources/omnibox_result_loader.js

Index: chrome/browser/resources/omnibox_result_loader.js
diff --git a/chrome/browser/resources/omnibox_result_loader.js b/chrome/browser/resources/omnibox_result_loader.js
new file mode 100644
index 0000000000000000000000000000000000000000..322cebd0a38388ca20b69397b4aff5021925a6e2
--- /dev/null
+++ b/chrome/browser/resources/omnibox_result_loader.js
@@ -0,0 +1,93 @@
+/**
+ * @fileoverview Orchestrates loading of suggestion content in several
+ * chrome-search://suggestion iframes.
+ */
+
+/**
+ * The origin of the embedding page.
+ * Must be in double quotes for proper escaping.
+ * @type {string}
+ * @const
+ */
+var EMBEDDER_ORIGIN = "%s";
+
+/**
+ * Checks whether a string is a valid color code.
+ * @param {string} color A color code.
+ * @return {boolean} True if color is a valid color code and false otherwise.
+ */
+function isValidColor(color) {
+  // Accept 3 or 6 digit hex colors preceded by '#'.
+  return /^#[0-9A-Fa-f]{3}|#[0-9A-Fa-f]{6}$/.test(color);
+}
+
+/**
+ * Checks and returns suggestion style.
+ * @param {Object} userStyle User-specified overrides for suggestion styles.
+ * @return {Object} Checked styles or defaults.
+ */
+function getStyle(userStyle) {
+  var apiHandle = chrome.embeddedSearch.searchBox;
+  var safeStyle = {
+    urlColor: '#093',
+    titleColor: '#666',
+    font: apiHandle.font,
+    fontSize: apiHandle.fontSize
+  };
+  if ('urlColor' in userStyle && isValidColor(userStyle.urlColor))
+    safeStyle.urlColor = userStyle.urlColor;
+  if ('titleColor' in userStyle && isValidColor(userStyle.titleColor))
+    safeStyle.titleColor = userStyle.titleColor;
+  return safeStyle;
+}
+
+/**
+ * Renders a native history suggestion.
+ * @param {Document} resultDoc The suggestion template document.
+ * @param {Object} suggestion The NativeSuggestion to render.
+ * @param {Object} style Checked (not user-set) result style.
+ */
+function updateResult(resultDoc, suggestion, style) {
+  resultDoc.body.style.font = style.fontSize + 'px "' + style.font + '";';
+  var urlNode = resultDoc.querySelector('#url');
+  urlNode.textContent = suggestion.destination_url;
+  urlNode.style.color = style.urlColor;
+  var optionalNode = resultDoc.querySelector('#optional');
+  if (suggestion.description) {
+    var titleNode = resultDoc.querySelector('#title');
+    titleNode.textContent = suggestion.description;
+    optionalNode.style.color = style.titleColor;
+    optionalNode.classList.remove('hide');
+  } else {
+    optionalNode.classList.add('hide');
+  }
+}
+
+/**
+ * Handles a postMessage from the embedding page requesting to populate history
+ * suggestion iframes.
+ * @param {Object} message The message.
+ */
+function handleMessage(message) {
+  // Only allow messages from the embedding page, which should be an Instant
+  // search provider or the local omnibox dropdown (and not e.g. a site which
+  // it has iframed.)
+  if (message.origin != EMBEDDER_ORIGIN)
+    return;
+  var apiHandle = chrome.embeddedSearch.searchBox;
+  if ('load' in message.data) {
+    var loaded = [];
+    for (var id in message.data.load) {
+      var restrictedId = message.data.load[id];
+      var suggestion = apiHandle.getSuggestionData(restrictedId);
+      updateResult(window.parent.frames[id].document, suggestion,

[sreeram, 2013/04/01 21:03:27]

Where's the "frames" array defined?

[Jered, 2013/04/01 21:29:18]

This is referencing window.frames
https://developer.mozilla.org/en-US/docs/DOM/window.frames

[sreeram, 2013/04/01 21:50:41]

Correct me if I am wrong: window.parent refers to the embedder page, right? How
does this work across origins? (This script is executing in a
chrome-search://suggestion/ origin, whereas the embedder is either
https://www.google.com/ or chrome-search://local-omnibox-popup/.)

+          getStyle(message.data.style || {}));
+      loaded.push(id);
+    }
+    message.source.postMessage(
+        {'loaded': message.data.requestId},
+        message.origin);
+  }
+}
+
+window.addEventListener('message', handleMessage, false);