hwc/overlay: Introduce padding round between DMA modes.

Introduce a padding round between the DMA line and block modes.
Do this based on whether DMA is actually being used, when block mode
is first requested.

This relieves the driver of doing an UNSET ahead of vsync which could
cause blinks in all such transition scenarios.

This approach should lead to smooth transitions for multiple targets
with the exception of secure videos, where there could be a blink in
any of the different approaches we use.

Change-Id: Ibc0b8d284b5c6ed9291a7cfa7e7f221300a921e2

libhwcomposer/hwc_utils.cpp

@@ -344,6 +344,9 @@ void setListStats(hwc_context_t *ctx,
             yuvCount++;
 
             if(layer->transform & HWC_TRANSFORM_ROT_90) {
+                if(ctx->mOverlay->isPipeTypeAttached(OV_MDP_PIPE_DMA)) {
+                    ctx->isPaddingRound = true;
+                }
                 Overlay::setDMAMode(Overlay::DMA_BLOCK_MODE);
             }
         }