am a84ca8a3: Merge "TextureView/GLES20Canvas: Support synchronous GLConsumers" into klp-dev

    sp<GLConsumer> surfaceTexture(SurfaceTexture_getSurfaceTexture(env, surface));

    if (surfaceTexture->updateTexImage() == NO_ERROR) {

        int64_t frameNumber = surfaceTexture->getFrameNumber();

        // If the GLConsumer queue is in synchronous mode, need to discard all

        // but latest frame, using the frame number to tell when we no longer

        // have newer frames to target. Since we can't tell which mode it is in,

        // do this unconditionally.

        int dropCounter = 0;

        while (surfaceTexture->updateTexImage() == NO_ERROR) {

            int64_t newFrameNumber = surfaceTexture->getFrameNumber();

            if (newFrameNumber == frameNumber) break;

            frameNumber = newFrameNumber;

            dropCounter++;

        }

        #if DEBUG_RENDERER

        if (dropCounter > 0) {

            RENDERER_LOGD("Dropped %d frames on texture layer update", dropCounter);

        }

        #endif

        surfaceTexture->getTransformMatrix(transform);

        GLenum renderTarget = surfaceTexture->getCurrentTextureTarget();