Fix bug 4080407 - Browser stuck after scrolling- page stops responding
Fix bug 4080407 - Browser stuck after scrolling- page stops responding

Account for gaps in touch queue sequence numbering when we flush out
canceled events from webcore's queue. Add a 2-second timeout to auto-flush
old events when a new gesture begins.

Change-Id: I764a7fcd673b3afb629055b001e9346f5b959dba

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