Fixed Screenshot extension example

BUG=

Review URL: https://codereview.chromium.org/490133002

Cr-Commit-Position: refs/heads/master@{#291874}

chrome/common/extensions/docs/examples/api/tabs/screenshot/background.js

@@ -9,49 +9,41 @@
 // open.
 var id = 100;
 
-function takeScreenshot() {
-  chrome.tabs.captureVisibleTab(null, function(img) {
-    var screenshotUrl = img;
-    var viewTabUrl = chrome.extension.getURL('screenshot.html?id=' + id++)
+// Listen for a click on the camera icon. On that click, take a screenshot.
+chrome.browserAction.onClicked.addListener(function() {
 
-    chrome.tabs.create({url: viewTabUrl}, function(tab) {
-      var targetId = tab.id;
+  chrome.tabs.captureVisibleTab(function(screenshotUrl) {
+    var viewTabUrl = chrome.extension.getURL('screenshot.html?id=' + id++)
+    var targetId = null;
 
-      var addSnapshotImageToTab = function(tabId, changedProps) {
-        // We are waiting for the tab we opened to finish loading.
-        // Check that the the tab's id matches the tab we opened,
-        // and that the tab is done loading.
-        if (tabId != targetId || changedProps.status != "complete")
-          return;
+    chrome.tabs.onUpdated.addListener(function listener(tabId, changedProps) {
+      // We are waiting for the tab we opened to finish loading.
+      // Check that the tab's id matches the tab we opened,
+      // and that the tab is done loading.
+      if (tabId != targetId || changedProps.status != "complete")
+        return;
 
-        // Passing the above test means this is the event we were waiting for.
-        // There is nothing we need to do for future onUpdated events, so we
-        // use removeListner to stop geting called when onUpdated events fire.
-        chrome.tabs.onUpdated.removeListener(addSnapshotImageToTab);
+      // Passing the above test means this is the event we were waiting for.
+      // There is nothing we need to do for future onUpdated events, so we
+      // use removeListner to stop getting called when onUpdated events fire.
+      chrome.tabs.onUpdated.removeListener(listener);
 
-        // Look through all views to find the window which will display
-        // the screenshot.  The url of the tab which will display the
-        // screenshot includes a query parameter with a unique id, which
-        // ensures that exactly one view will have the matching URL.
-        var views = chrome.extension.getViews();
-        for (var i = 0; i < views.length; i++) {
-          var view = views[i];
-          if (view.location.href == viewTabUrl) {
-            view.setScreenshotUrl(screenshotUrl);
-            break;
-          }
+      // Look through all views to find the window which will display
+      // the screenshot.  The url of the tab which will display the
+      // screenshot includes a query parameter with a unique id, which
+      // ensures that exactly one view will have the matching URL.
+      var views = chrome.extension.getViews();
+      for (var i = 0; i < views.length; i++) {
+        var view = views[i];
+        if (view.location.href == viewTabUrl) {
+          view.setScreenshotUrl(screenshotUrl);
+          break;
         }
-      };
-      chrome.tabs.onUpdated.addListener(addSnapshotImageToTab);
+      }
     });
-  });
-}
 
-// Listen for a click on the camera icon.  On that click, take a screenshot.
-chrome.browserAction.onClicked.addListener(function(tab) {
-  if (tab.url.match("^https?://code.google.com")) {
-    takeScreenshot();
-  } else {
-    alert('This sample can only take screenshots of code.google.com pages');
-  }
+    chrome.tabs.create({url: viewTabUrl}, function(tab) {
+      targetId = tab.id;
+    });
+  });
 });

chrome/common/extensions/docs/examples/api/tabs/screenshot/manifest.json

 {
   "name": "Test Screenshot Extension",
-  "version": "1.2",
-  "description": "Demonstrate screenshot functionality in the chrome.tabs api. Note: only works for code.google.com",
+  "version": "1.3",
+  "description": "Demonstrate screenshot functionality in the chrome.tabs api.",
   "background": {
     "persistent": false,
     "scripts": ["background.js"]
@@ -11,7 +11,7 @@
     "default_title": "Take a screen shot!"
   },
   "permissions": [
-    "*://code.google.com/"
+    "activeTab"
   ],
   "manifest_version": 2
 }

chrome/common/extensions/docs/examples/api/tabs/screenshot/screenshot.html

@@ -3,7 +3,7 @@
 <body>
   Image here:
   <p>
-    <img id="target" src="white.png" width="640" height="480">
+    <img id="target" src="white.png" height="480">
   <p>
   End image
   </body>