[Android WebView] Send WebChromeClient.onReceivedTitle when navigating back

[Android WebView] Send WebChromeClient.onReceivedTitle when navigating back

This is a re-land of https://codereview.chromium.org/1126383005, fixed
not to cause a crash when 'WebView.loadUrl' is called from inside the
onReceivedTitle callback, added a regression test. Also, the document
title is now cached to minimize the amount of callback calls.

Original patch description:

The usual channel for delivering onReceivedTitle (via updating title for
a NavigationEntry) doesn't work in the case of history navigations, because
WebContentsImpl silences no-op updates of entries titles.

Chrome Browser uses another event for updating the title in this case --
via WebContentsDelegate::LoadingStateChanged. This patch enables WebView to
use it as well.

Note that WebChromeClient.onReceivedIcon doesn't need to be re-sent, as
nobody seems to bother checking whether the icon update is a "no-op", so
updates on history navigations just work.

BUG=481570, 495234
Committed: https://crrev.com/27cdc32e21149f7bc890ddd9347e4a963e4899ee
Cr-Commit-Position: refs/heads/master@{#333056}

[mnaganov (inactive), 2015-06-02 16:28:15]

mnaganov@chromium.org changed reviewers:
+ torne@chromium.org

[Torne, 2015-06-04 13:28:47]

Just one question; if that's not a problem then LGTM.

https://codereview.chromium.org/1161783005/diff/1/android_webview/java/src/or...
File android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
(right):

https://codereview.chromium.org/1161783005/diff/1/android_webview/java/src/or...
android_webview/java/src/org/chromium/android_webview/AwContentsClient.java:52:
// so behaviours are consistent.
Is this going to cause us to emit *fewer* onReceivedTitle callbacks than the old
behaviour, in the case where a navigation goes from one page to another page
with the same title? Or were we already only triggering one callback in that
case?

[mnaganov (inactive), 2015-06-04 23:27:36]

https://codereview.chromium.org/1161783005/diff/1/android_webview/java/src/or...
File android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
(right):

https://codereview.chromium.org/1161783005/diff/1/android_webview/java/src/or...
android_webview/java/src/org/chromium/android_webview/AwContentsClient.java:52:
// so behaviours are consistent.
On 2015/06/04 13:28:47, Torne wrote:
> Is this going to cause us to emit *fewer* onReceivedTitle callbacks than the
old
> behaviour, in the case where a navigation goes from one page to another page
> with the same title? Or were we already only triggering one callback in that
> case?

Thanks for raising this concern! I checked, and the reference behaviour is to
emit onReceivedTitle even if two pages have the same title. So I added a
regression test for that, and modified the code accordingly. You will probably
want to take another quick look.

[Torne, 2015-06-05 14:37:31]

Thanks, LGTM now other than one typo. It would be nice if we could assume apps
only use onReceivedTitle to update their UI but alas we know that's not the case
and they drive behaviour from it too, so this change is needed :(

https://codereview.chromium.org/1161783005/diff/20001/android_webview/javates...
File
android_webview/javatests/src/org/chromium/android_webview/test/LoadUrlTest.java
(right):

https://codereview.chromium.org/1161783005/diff/20001/android_webview/javates...
android_webview/javatests/src/org/chromium/android_webview/test/LoadUrlTest.java:386:
public void testOnReceivedTitleForUnchaningTitle() throws Throwable {
typo: should be "Unchanging"

[mnaganov (inactive), 2015-06-05 15:15:32]

On 2015/06/05 14:37:31, Torne wrote:
> Thanks, LGTM now other than one typo. It would be nice if we could assume apps
> only use onReceivedTitle to update their UI but alas we know that's not the
case
> and they drive behaviour from it too, so this change is needed :(
> 
>
https://codereview.chromium.org/1161783005/diff/20001/android_webview/javates...
> File
>
android_webview/javatests/src/org/chromium/android_webview/test/LoadUrlTest.java
> (right):
> 
>
https://codereview.chromium.org/1161783005/diff/20001/android_webview/javates...
>
android_webview/javatests/src/org/chromium/android_webview/test/LoadUrlTest.java:386:
> public void testOnReceivedTitleForUnchaningTitle() throws Throwable {
> typo: should be "Unchanging"

Fixed, thanks!

[mnaganov (inactive), 2015-06-05 15:15:37]

The CQ bit was checked by mnaganov@chromium.org

[mnaganov (inactive), 2015-06-05 15:15:38]

The patchset sent to the CQ was uploaded after l-g-t-m from torne@chromium.org
Link to the patchset: https://codereview.chromium.org/1161783005/#ps40001
(title: "Fixed typo")

[commit-bot: I haz the power, 2015-06-05 15:16:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1161783005/40001

[commit-bot: I haz the power, 2015-06-05 15:40:43]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-06-05 15:42:35]

Patchset 3 (id:??) landed as
https://crrev.com/27cdc32e21149f7bc890ddd9347e4a963e4899ee
Cr-Commit-Position: refs/heads/master@{#333056}