Change the pageaction_by_content example to use declarativeContent.

The "Mappy" sample still provides an example of a content script searching for
text.

The new icon comes from http://en.wikipedia.org/wiki/File:Video_icon2.png, which
is public domain.

TEST=Install the extension, and visit http://www.html5rocks.com/en/tutorials/video/basics/. The page action icon should show up.
BUG=330359
NOTRY=true

Review URL: https://codereview.chromium.org/124603003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243475 0039d316-1c4b-4281-b951-d872f2087c98

chrome/common/extensions/docs/examples/api/pageAction/pageaction_by_content/background.js

@@ -2,16 +2,18 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Called when a message is passed.  We assume that the content script
-// wants to show the page action.
-function onRequest(request, sender, sendResponse) {
-  // Show the page action for the tab that the sender (content script)
-  // was on.
-  chrome.pageAction.show(sender.tab.id);
-
-  // Return nothing to let the connection be cleaned up.
-  sendResponse({});
-};
-
-// Listen for the content script to send a message to the background page.
-chrome.extension.onRequest.addListener(onRequest);
+// Update the declarative rules on install or upgrade.
+chrome.runtime.onInstalled.addListener(function() {
+  chrome.declarativeContent.onPageChanged.removeRules(undefined, function() {
+    chrome.declarativeContent.onPageChanged.addRules([{
+      conditions: [
+        // When a page contains a <video> tag...
+        new chrome.declarativeContent.PageStateMatcher({
+          css: ["video"]
+        })
+      ],
+      // ... show the page action.
+      actions: [new chrome.declarativeContent.ShowPageAction() ]
+    }]);
+  });
+});

chrome/common/extensions/docs/examples/api/pageAction/pageaction_by_content/contentscript.js

-/*
- * Copyright (c) 2010 The Chromium Authors. All rights reserved.  Use of this
- * source code is governed by a BSD-style license that can be found in the
- * LICENSE file.
- */
-var regex = /sandwich/;
-
-// Test the text of the body element against our regular expression.
-if (regex.test(document.body.innerText)) {
-  // The regular expression produced a match, so notify the background page.
-  chrome.extension.sendRequest({}, function(response) {});
-} else {
-  // No match was found.
-}

chrome/common/extensions/docs/examples/api/pageAction/pageaction_by_content/manifest.json

 {
   "name" : "Page action by content",
   "version" : "1.1",
-  "description" : "Shows a page action for HTML pages containing the word 'sandwich'",
+  "description" : "Shows a page action for HTML pages containing a video",
   "background" : {
-    "scripts": ["background.js"]
+    "scripts": ["background.js"],
+    "persistent": false
   },
   "page_action" :
   {
-    "default_icon" : "sandwich-19.png",
-    "default_title" : "There's a 'sandwich' in this page!"
+    "default_icon" : "video-19.png",
+    "default_title" : "There's a <video> in this page!"
   },
-  "content_scripts" : [
-    {
-      "matches" : [
-        "http://*/*",
-        "https://*/*"
-      ],
-      "js" : ["contentscript.js"],
-      "run_at" : "document_idle",
-      "all_frames" : false
-    }
-  ],
+  "permissions": [ "declarativeContent" ],
   "icons" : {
-    "48" : "sandwich-48.png",
-    "128" : "sandwich-128.png"
+    "48" : "video-48.png",
+    "128" : "video-128.png"
   },
   "manifest_version": 2
-}
+}
\ No newline at end of file