Wait for buffers to be latched in ChildLayerTest

Fixes: 176596429
Test: atest SurfaceFlinger_test:ChildLayerTest --rerun-until-failure 100
Change-Id: I3dd3258c6e1f3669cf71df6cbe39a537f336c6a5

parent 2fc978ff

services/surfaceflinger/tests/LayerUpdate_test.cpp

+1 −0

Original line number	Diff line number	Diff line
		@@ -299,6 +299,7 @@ protected:
		mChild = createSurface(mClient, "Child surface", 10, 15, PIXEL_FORMAT_RGBA_8888, 0,
		mFGSurfaceControl.get());
		TransactionUtils::fillSurfaceRGBA8(mChild, 200, 200, 200);
		waitForPostedBuffers();

		{
		SCOPED_TRACE("before anything");