b/3340946 Fix NPE caused by null gesture detector.
b/3340946 Fix NPE caused by null gesture detector.

Gmail use WebView without instantiating the gesture detector. The Gmail team replied that they don't need the pinch to zoom feature so we can safely skip multi-touch events for them.

Change-Id: Id60a4d4583979ef5b420fff04c4ca097c0594024

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