Check for null mWebViewCore in selectText
Check for null mWebViewCore in selectText

 Bug 6306770

Change-Id: I83e70aef45ff6519e4e9eb70edae44efcecf6de8

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base