i965: Implement EGL_KHR_mutable_render_buffer

Testing:
  - Manually tested a low-latency handwriting demo that toggles
    EGL_RENDER_BUFFER. Toggling changed the display latency as expected.
    Used Android on Chrome OS, Kabylake GT2.
  - No change in dEQP-EGL.functional.* on Fedora 27, Wayland, Skylake
    GT2.  Used deqp at tag android-p-preview-5.
  - No regressions in dEQP-EGL.functional.*, ran on Android on Chrome
    OS, Kabylake GT2. Some dEQP-EGL.functional.mutable_render_buffer.*
    test change from NotSupported to Pass.

Reviewed-by: Tapani Pälli <[email protected]>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_context.h b/src/mesa/drivers/dri/i965/brw_context.h
index c32def7c3d7..d3b96953467 100644
--- a/src/mesa/drivers/dri/i965/brw_context.h
+++ b/src/mesa/drivers/dri/i965/brw_context.h
@@ -791,6 +791,18 @@ struct brw_context
     */
    bool front_buffer_dirty;
 
+   /**
+    * True if the __DRIdrawable's current __DRIimageBufferMask is
+    * __DRI_IMAGE_BUFFER_SHARED.
+    */
+   bool is_shared_buffer_bound;
+
+   /**
+    * True if a shared buffer is bound and it has received any rendering since
+    * the previous __DRImutableRenderBufferLoaderExtension::displaySharedBuffer().
+    */
+   bool is_shared_buffer_dirty;
+
    /** Framerate throttling: @{ */
    struct brw_bo *throttle_batch[2];