tree 5b56bfaed22c67b7580adaa272b6d4b59c9cf100
parent 5e9a43e006a185fa43409c7fdb6c32d5bb786e70
author Chia-I Wu <olv@google.com> 1525453957 -0700
committer Chia-I Wu <olv@google.com> 1525472973 -0700

surfaceflinger: switch RE color matrices lazily

Client composition in doComposeSurfaces normally needs to handle

  N sRGB layers, when in ColorMode::SRGB
  N P3 layer and then M sRGB layers, when in ColorMode::DISPLAY_P3

Constantly switching and restoring RE color matrices when handling
sRGB layers is less efficient.  Do the switches lazily.

We don't really care about the current RE color matrix when
doComposeSurfaces is called, and we already assume it to be
identity.  Update RenderEngine::setupColorTransform not to return
the current color matrix.

Bug: 78891890
Test: night light under Boosted/Enhanced and sRGB/P3
Change-Id: I3b785c2a05f2e1679e486ab2497fc0e13993a791