Ensure that renderer-initiated pending entries can be replaced when a new navigation is started.

Ensure that renderer-initiated pending entries can be replaced when a new 
navigation is started. 

We don't replace browser-initiated pending entries in didStartProvisionalLoad 
because either (1) they were just created for this navigation, or (2) they're 
for a different SiteInstance and won't be used upon commit. 

Note that pending entries for same-site browser-initiated navigations can be 
incorrectly used for renderer-initiated navigations that interrupt them, but 
that's a long standing bug that we can address separately. 

BUG=266922
TEST=See bug for repro steps.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=216548

[Charlie Reis, 2013-08-07 21:34:58]

Hey Brett--
  Here's an updated version of https://codereview.chromium.org/21913003/, which
was reverted because it caused PlatformAppBrowserTest.DisallowNavigation to
fail.  Turns out we were replacing the pending entry with
data:text/html,chromewebdata for error pages, which we now avoid.  Can you take
a look?

Charlie

https://codereview.chromium.org/22622003/diff/3001/content/browser/web_conten...
File content/browser/web_contents/navigation_controller_impl_unittest.cc
(right):

https://codereview.chromium.org/22622003/diff/3001/content/browser/web_conten...
content/browser/web_contents/navigation_controller_impl_unittest.cc:2652: // We
should not replace the pending entry for an error URL.
Added a test for the error page here.

https://codereview.chromium.org/22622003/diff/3001/content/browser/web_conten...
File content/browser/web_contents/web_contents_impl.cc (right):

https://codereview.chromium.org/22622003/diff/3001/content/browser/web_conten...
content/browser/web_contents/web_contents_impl.cc:2148: if
(!has_browser_initiated_pending_entry && !is_error_page) {
The fix was to check for !is_error_page here, since we don't want that to
replace the pending entry for the page the error is about.

[brettw, 2013-08-08 20:43:52]

lgtm

[commit-bot: I haz the power, 2013-08-08 20:46:53]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/creis@chromium.org/22622003/9001

[commit-bot: I haz the power, 2013-08-09 02:38:45]

Change committed as 216548