gpu: Empty swaps for surfaceless output surfaces.

cc/output/overlay_unittest.cc

Index: cc/output/overlay_unittest.cc
diff --git a/cc/output/overlay_unittest.cc b/cc/output/overlay_unittest.cc
index c989fbd2503fa74edc23bdc393eac9fbd3df5177..ee804f369ef6de73701e5204745e07f22cf8287a 100644
--- a/cc/output/overlay_unittest.cc
+++ b/cc/output/overlay_unittest.cc
@@ -2190,7 +2190,7 @@ TEST_F(GLRendererWithOverlaysTest, OccludedQuadNotDrawnWhenPartialSwapEnabled) {
   EXPECT_CALL(*renderer_, DoDrawQuad(_, _)).Times(0);
   EXPECT_CALL(scheduler_, Schedule(_, _, _, _, _)).Times(2);
   DrawFrame(&pass_list, viewport_size);
-  EXPECT_EQ(1U, output_surface_->bind_framebuffer_count());
+  EXPECT_EQ(0U, output_surface_->bind_framebuffer_count());
   SwapBuffers();
   Mock::VerifyAndClearExpectations(renderer_.get());
   Mock::VerifyAndClearExpectations(&scheduler_);
@@ -2222,7 +2222,7 @@ TEST_F(GLRendererWithOverlaysTest, OccludedQuadNotDrawnWhenEmptySwapAllowed) {
   EXPECT_CALL(*renderer_, DoDrawQuad(_, _)).Times(0);
   EXPECT_CALL(scheduler_, Schedule(_, _, _, _, _)).Times(2);
   DrawFrame(&pass_list, viewport_size);
-  EXPECT_EQ(1U, output_surface_->bind_framebuffer_count());
+  EXPECT_EQ(0U, output_surface_->bind_framebuffer_count());
   SwapBuffers();
   Mock::VerifyAndClearExpectations(renderer_.get());
   Mock::VerifyAndClearExpectations(&scheduler_);