fix [2420565] Surface.lockCanvas() updates the dirty region too often
fix [2420565] Surface.lockCanvas() updates the dirty region too often

There was a bug where we were we could be reallocating buffers for no reason.

Change-Id: Ieb8a81a289da9339ab7faf987cd3a73428943c1a

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