WebUI: DisallowJavascript only on Refresh and non-same-page navigations

chrome/browser/ui/webui/settings/md_settings_ui_browsertest.cc

 // Copyright 2016 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.
 
 #include <string>
 
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/url_constants.h"
@@ skipping 42 matching lines @@
 
   auto handlers = browser()->tab_strip_model()->GetActiveWebContents()
       ->GetWebUI()->GetHandlersForTesting();
 
   for (content::WebUIMessageHandler* handler : *handlers) {
     handler->AllowJavascriptForTesting();
     handler->DisallowJavascript();
     handler->AllowJavascriptForTesting();
   }
 }
+
+IN_PROC_BROWSER_TEST_F(MdSettingsUITest, InPageNavigationsAndReload) {
+  NavigateToURL(browser(), GURL(chrome::kChromeUIMdSettingsURL));
+
+  auto handlers = browser()->tab_strip_model()->GetActiveWebContents()
+      ->GetWebUI()->GetHandlersForTesting();
+  for (content::WebUIMessageHandler* handler : *handlers)
+    handler->AllowJavascriptForTesting();
+
+  // Push onto window.history. Back should now be an in-page navigation.
+  ASSERT_TRUE(content::ExecuteScript(
+      browser()->tab_strip_model()->GetActiveWebContents(),
+     "window.history.pushState({}, '', 'foo.html')"));
+  chrome::GoBack(browser(), CURRENT_TAB);
+  WaitForLoadStop(browser()->tab_strip_model()->GetActiveWebContents());
+
+  for (content::WebUIMessageHandler* handler : *handlers)
+    EXPECT_TRUE(handler->IsJavascriptAllowed());
+
+  chrome::Reload(browser(), CURRENT_TAB);
+  WaitForLoadStop(browser()->tab_strip_model()->GetActiveWebContents());
+
+  // Verify that after a reload, at least some of the handlers are disallowed.

[Charlie Reis, 2016/06/25 00:17:02]

I'm not sure I understand this.  Wouldn't all of the handlers come back if you
waited long enough?  Or do some of them go away permanently when you reload? 
(Why would that be?)

[tommycli, 2016/06/25 00:21:51]

Some of the handlers only are used on subpages. They are not 'activated' until
they receive their first chrome.send message they need to handle.

Since we are loading the main page only, some of these subpage handlers are
never activated.

[tommycli, 2016/06/25 00:22:50]

I'm trying to test that on Reload, the handlers are all disabled.

I'm totally open to a better way of testing this, since this way is confusing
and kind of lame.

[Charlie Reis, 2016/06/27 21:31:31]

Hmm.  Would the list of enabled handlers match the list after line 65, before we
loop through and call AllowJavascriptForTesting on them on line 67?  Maybe we
could grab the ones that are disabled and ensure they're disabled again after
the reload?  (I'm not sure if it's that simple.)
Another option might be adding a test message handler that can listen for
whether disallow and allow were called on it.

[tommycli, 2016/06/27 21:56:08]

Ah yes. Using the test handler was the best suggestion IMO.

Since it was a test handler I was also able to use chrome://terms instead of
chrome://md-settings (much faster to run browsertest), and the test retains the
power it had.

I moved this test to webui_browsertest.cc btw, and renamed the tests there to
WebUIImplBrowserTest, since there was already a WebUIBrowserTest class and the
name collided.

+  bool all_handlers_allowed = true;
+  for (content::WebUIMessageHandler* handler : *handlers) {
+    if (!handler->IsJavascriptAllowed())
+      all_handlers_allowed = false;
+  }
+  EXPECT_FALSE(all_handlers_allowed);
+}