SF: Fix invalid reduction of transparent region from a layer.

Reduce transparent region from a layer only if the transparent
region has valid intersection with the layer. Otherwise, reducing
a transparent region lying completely outside of the layer leads to
invalid sourcecrop values for the layer.

Change-Id: Iee9ba53a8072c21c9ba8a6d58cb14ca30f8600ba
CRs-Fixed: 620973
sf: Determine if virtual display can use HWC for composition

For HWC virtual display using V4L2 approach:
1. HWC virtual display implementation doesn't send output buffer
   back to Surface Flinger.
2. For non-wfd virtual displays(e.g. Simulated Secondary Displays,
   Screen Record, CTS etc..), configure VDS to use GPU for
   composition on output/sink buffer.
3. For wfd virtual display (a.k.a hybrid wfd), use
   Framebuffer surface (similar to external display mechanism).

For HWC virtual display using VDS approach:
1. HWC is allocated for first virtual display connection.
2. Subsequent virtual display sessions will be composed by GLES driver.
ToDo: Modify VDS component to allocate hwcDisplayId based on
mForceHwcCopy (which is based on Usage Flags)

Change-Id: Ib7d2c00ca5fa07908b2eac8085654f8d2cd9af0b

Conflicts:
	services/surfaceflinger/DisplayHardware/HWComposer.cpp
	services/surfaceflinger/DisplayHardware/HWComposer.h
fix this and re do some commits

Change-Id: I6b47e10ce82fcb8b3f0cd06f6f4a9fa7d48a070c
SF: Add flag for swaprect status in HAL

We need to check in HAL whether swap rect
is enable or disable to calculate wormhole region.

Change-Id: I4fbff4119856e41694e2065141b40fdd7a15f375
SurfaceFlinger: Change to support framebuffer flip for 2D blitters

- Surfaceflinger does not flip framebuffers when there are
  no layers marked for HWC_FRAMEBUFFER
- This change checks for the HWC_BLIT flag and will request a flip
  to a new FB_TARGET buffer even if there are no FRAMEBUFFER layers

Change-Id: I1cb44389a05c9ec049d7f0d39c288feccb11a91c
Display: Define new composition type for blit composition

This change defines a new flag 'hasBlitComp' to identify
blit composition. This flag is used to enable the swap rect
feature for blit composition cases.

Change-Id: Ic523e19796a893efbfc3bff300d1f982cba5ddfa
Revert "Add sessionId metadata with every buffer queued through Surface"

This reverts commit 85743373ed7d4eb6cb58412bda6c74f9ee29f06f.
This change is no longer needed

Change-Id: Ia5612b42f081236db65ac8eef9d359dfd23f4117
sf: Determine if virtual display can use HWC for composition

For HWC virtual display using V4L2 approach:
1. HWC virtual display implementation doesn't send output buffer
   back to Surface Flinger.
2. For non-wfd virtual displays(e.g. Simulated Secondary Displays,
   Screen Record, CTS etc..), configure VDS to use GPU for
   composition on output/sink buffer.
3. For wfd virtual display (a.k.a hybrid wfd), use
   Framebuffer surface (similar to external display mechanism).

For HWC virtual display using VDS approach:
1. HWC is allocated for first virtual display connection.
2. Subsequent virtual display sessions will be composed by GLES driver.
ToDo: Modify VDS component to allocate hwcDisplayId based on
mForceHwcCopy (which is based on Usage Flags)

Change-Id: Ib7d2c00ca5fa07908b2eac8085654f8d2cd9af0b

Conflicts:
	services/surfaceflinger/DisplayHardware/HWComposer.h