WebContentsImpl owns a WebContentsViewAura, which is a 
parent of the RenderWidgetHostViewAura.  WCI would set the 
visibility of the WCVA, which would then notify both the 
WCVA and its child, the RWHVA, that its visibility had been 
updated even though it never actually updated the visibility 
of the RWHVA.  This patch addresses that.

Additionally, we apply a speculative fix for a perf 
regression in peak memory usage, by attempting to unload a 
large resource before loading a new large resource (instead 
of the other way around).

BUG=297567, 298170, 297764, 297831, 297815

Review URL: https://codereview.chromium.org/23484067

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225363 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225363
Override PrerequisiteKeys to make sure OptionsPage is initialized.

This change ensures to show a configuration button when the extension IME is enabled.

BUG=290015

Review URL: https://codereview.chromium.org/23498040

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225364 0039d316-1c4b-4281-b951-d872f2087c98
Refactor webcrypto unittests.

Extracts some helper functions which will be re-used for AES-CBC tests. Notably, importing of secret keys and comparison of arraybuffer against hex string.

BUG=245025

Review URL: https://codereview.chromium.org/24237013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225365 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225364
Media Galleries: Refactor test to not need RunSecondPhase().

Review URL: https://codereview.chromium.org/24242010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225366 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225366