HWC: Fix for use int reference in function call

To use the integer reference, declared integer
variable to get value directly in that variable.

Change-Id: I1fd1a45580be99dd95ccbc3495e28455a4c7de23
hwcomposer : Fix rotator fence for FB pre rotation.

Add framebuffer to rotator map data structure if
rotator is used for pre rotating framebuffer.

Change-Id: I496656c22b289b0bb0bf8c49056384a7fad3ac7d
CRs-fixed: 569696

Conflicts:
	libhwcomposer/hwc_fbupdate.cpp
hwc: Add deduction operation to Rect utils

Seperate out rectangle deduction from the layer cropping. Update
layer sourceCrop and displayFrame after deducting the rect value.
This makes the function generic enough to be used by other
modules

Change-Id: I587ac951357af823a1bf5e06c15ff47ac6a9c2a0
hwc: Crop source rect for the optimized destination

If a layer destination can be optimized, its source rect
needs to be cropped for the optimized destination rect.

Change-Id: If9a9891200d9cea52b58b253299b4007197cd9e5