fix($sniffer): fix history sniffing in Chrome Packaged Apps

Although `window.history` is present in the context of Chrome Packaged Apps, it is not allowed to
access `window.history.pushState` or `window.history.state`, resulting in errors when trying to
"sniff" history support.
This commit fixes it by detecting a Chrome Packaged App (through the presence of
`window.chrome.app.runtime`). Note that `window.chrome.app` is present in the context of "normal"
webpages as well, but it doesn't have the `runtime` property, which is only available to packaged
apps (e.g. see https://developer.chrome.com/apps/api_index).

(It also also contains some style changes for making the structure and layout of `$sniffer` tests
 more consistent.)

Fixes #11932

Closes #13945

Author: gkalpak

src/ng/browser.js

@@ -86,7 +86,14 @@ function Browser(window, document, $log, $sniffer) {
   var cachedState, lastHistoryState,
       lastBrowserUrl = location.href,
       baseElement = document.find('base'),
-      pendingLocation = null;
+      pendingLocation = null,
+      getCurrentState = !$sniffer.history ? noop : function getCurrentState() {
+        try {
+          return history.state;
+        } catch (e) {
+          // MSIE can reportedly throw when there is no state (UNCONFIRMED).
+        }
+      };
 
   cacheState();
   lastHistoryState = cachedState;
@@ -194,14 +201,6 @@ function Browser(window, document, $log, $sniffer) {
     fireUrlChange();
   }
 
-  function getCurrentState() {
-    try {
-      return history.state;
-    } catch (e) {
-      // MSIE can reportedly throw when there is no state (UNCONFIRMED).
-    }
-  }
-
   // This variable should be used *only* inside the cacheState function.
   var lastCachedState = null;
   function cacheState() {

src/ng/sniffer.js

@@ -17,6 +17,10 @@
 function $SnifferProvider() {
   this.$get = ['$window', '$document', function($window, $document) {
     var eventSupport = {},
+        // Chrome Packaged Apps are not allowed to access `history.pushState`. They can be detected by
+        // the presence of `chrome.app.runtime` (see https://developer.chrome.com/apps/api_index)
+        isChromePackagedApp = $window.chrome && $window.chrome.app && $window.chrome.app.runtime,
+        hasHistoryPushState = !isChromePackagedApp && $window.history && $window.history.pushState,
         android =
           toInt((/android (\d+)/.exec(lowercase(($window.navigator || {}).userAgent)) || [])[1]),
         boxee = /Boxee/i.test(($window.navigator || {}).userAgent),
@@ -61,7 +65,7 @@ function $SnifferProvider() {
       // so let's not use the history API also
       // We are purposefully using `!(android < 4)` to cover the case when `android` is undefined
       // jshint -W018
-      history: !!($window.history && $window.history.pushState && !(android < 4) && !boxee),
+      history: !!(hasHistoryPushState && !(android < 4) && !boxee),
       // jshint +W018
       hasEvent: function(event) {
         // IE9 implements 'input' event it's so fubared that we rather pretend that it doesn't have

test/ng/browserSpecs.js

@@ -545,9 +545,32 @@ describe('browser', function() {
       currentHref = fakeWindow.location.href;
     });
 
+    it('should not access `history.state` when `$sniffer.history` is false', function() {
+      // In the context of a Chrome Packaged App, although `history.state` is present, accessing it
+      // is not allowed and logs an error in the console. We should not try to access
+      // `history.state` in contexts where `$sniffer.history` is false.
+
+      var historyStateAccessed = false;
+      var mockSniffer = {histroy: false};
+      var mockWindow = new MockWindow();
+
+      var _state = mockWindow.history.state;
+      Object.defineProperty(mockWindow.history, 'state', {
+        get: function() {
+          historyStateAccessed = true;
+          return _state;
+        }
+      });
+
+      var browser = new Browser(mockWindow, fakeDocument, fakeLog, mockSniffer);
+
+      expect(historyStateAccessed).toBe(false);
+    });
+
     describe('in IE', runTests({msie: true}));
     describe('not in IE', runTests({msie: false}));
 
+
     function runTests(options) {
       return function() {
         beforeEach(function() {