[Telemetry]: Raise octane timeout for low-end devices.

Review URL: https://codereview.chromium.org/102383003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238623 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238623
Remove DCHECK(context3d_) checks that check nothing.

We only allow creation of ContextProvider with a non-null context3d
and store it in the class inside the constructor. This was not always
the case, and we had DCHECKs to verify behaviour. Now, a DCHECK in
the constructor is enough (though also stricly not needed since the
Create() function checks for NULL). Remove the other DCHECKs as they
are just noise.

R=piman@chromium.org
BUG=

Review URL: https://codereview.chromium.org/102493003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238624 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238624