Revert 224921 "Expose toggle fullscreen to observer."

Looks like the cause of Android compile failures
http://build.chromium.org/p/chromium.linux/builders/Android%20Builder%20%28dbg%29/builds/43692
http://build.chromium.org/p/chromium.linux/builders/Android%20Builder/builds/20118

> Expose toggle fullscreen to observer.
> 
> BUG=277135
> NOTRY=true
> 
> Review URL: https://chromiumcodereview.appspot.com/24303006

TBR=dtrainor@chromium.org

Review URL: https://codereview.chromium.org/24360014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224929 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224929
[InstantExtended] Investigate crash from check for search results page in TemplateURLRef::ExtractSearchTermsFromURL(..)

I suspect this crash is occuring from an invalid NavigationEntry and that GetURL() gets inlined which is why the crash is occurring much higher up the stack. However, I can't determine a good reason why that would be null. Adding a CHECK to see if we can get more information on why this crash is occurring.

BUG=291348

Review URL: https://chromiumcodereview.appspot.com/24255012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224930 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224930