[M85 Migration] Ensure ProduceTexture is executed before ConsumeTexture

[M85 Migration] Ensure ProduceTexture is executed before ConsumeTexture

Black patches are seen occasionally while navigating back and
forth between pages. This is a sync issue where ConsumeTexture
gets executed before ProduceTexture's execution is completed.

To fix this issue, we add glFlush and glError before renderer
submits a frame to the browser. This will ensure that execution
of ProduceTexture is completed before ConsumeTexture is called.

Reference:
https://review.tizen.org/gerrit/c/197968/

Change-Id: I6882269588d257da3c455c2aa575b43c26e1d958
Signed-off-by: Chandan Padhi <c.padhi@samsung.com>
Signed-off-by: uzair <uzair.jaleel@samsung.com>