sometimes SF would not process a surface resize

this would happen when a window started with size A, was
resized to B and immediately resized to A. In this situation
the erquested and active size would be the same, and SF
would think a transaction wasn't needed.

we fix this by always comparing the requested sizes.

Also, make sure to set mRefreshPending once we're sure
we have succesfully called updateTexImage().

Bug: 6580962
Change-Id: I2c48b4df7f05fd35c9e1d2dd82095b0f3d5a0b6a