[ios] Signal DidFinishLoad if target URL is invalid.

[ios] Signal DidFinishLoad if target URL is invalid.

Target URL can be invalid if Reload is called for empty navigation
manager. Empty Navigation Manager is a reasonable state when the only
pending item was a page with badd SSL cert and user Tapped Go Back.

BUG=598047
Review URL: https://codereview.chromium.org/1844363004

Cr-Commit-Position: refs/heads/master@{#385085}
(cherry picked from commit 8466be358c11657cb90fe148c10017573e6cabdc)

Committed: https://chromium.googlesource.com/chromium/src/+/b527df8f6c0fe8da64f67b58143ee34c4e6133be

[Eugene But (OOO till 7-30), 2016-04-05 21:48:41]

Description was changed from

==========
[ios] Signal DidFinishLoad if target URL is invalid.

Target URL can be invalid if Reload is called for empty navigation
manager. Empty Navigation Manager is a reasonable state when the only
pending item was a page with badd SSL cert and user Tapped Go Back.

BUG=598047

Review URL: https://codereview.chromium.org/1844363004

Cr-Commit-Position: refs/heads/master@{#385085}
(cherry picked from commit 8466be358c11657cb90fe148c10017573e6cabdc)
==========

to

==========
[ios] Signal DidFinishLoad if target URL is invalid.

Target URL can be invalid if Reload is called for empty navigation
manager. Empty Navigation Manager is a reasonable state when the only
pending item was a page with badd SSL cert and user Tapped Go Back.

BUG=598047

Review URL: https://codereview.chromium.org/1844363004

Cr-Commit-Position: refs/heads/master@{#385085}
(cherry picked from commit 8466be358c11657cb90fe148c10017573e6cabdc)

Committed:
https://chromium.googlesource.com/chromium/src/+/b527df8f6c0fe8da64f67b58143e...
==========

[Eugene But (OOO till 7-30), 2016-04-05 21:48:43]

Committed patchset #1 (id:1) manually as
b527df8f6c0fe8da64f67b58143ee34c4e6133be.