Set cc::Display visibility to false when going to the background.

content/browser/renderer_host/compositor_impl_android.cc

Index: content/browser/renderer_host/compositor_impl_android.cc
diff --git a/content/browser/renderer_host/compositor_impl_android.cc b/content/browser/renderer_host/compositor_impl_android.cc
index fff5edb377455b6abe81f8e9a36ca5d764c3e107..5112bfed6d3148916f59a6026193d685446ebf97 100644
--- a/content/browser/renderer_host/compositor_impl_android.cc
+++ b/content/browser/renderer_host/compositor_impl_android.cc
@@ -559,12 +559,16 @@ void CompositorImpl::SetVisible(bool visible) {
     if (display_.get() && HavePendingReadbacks())
       display_->ForceImmediateDrawAndSwapIfPossible();
 
+    if (display_)
+      display_->SetVisible(false);
     host_->SetVisible(false);
     host_->ReleaseCompositorFrameSink();
     has_compositor_frame_sink_ = false;
     pending_frames_ = 0;
     display_.reset();

[boliu, 2017/06/02 00:30:35]

we reset the display a few lines below, does this code really matter?

   } else {
+    if (display_)
+      display_->SetVisible(true);
     host_->SetVisible(true);
     if (compositor_frame_sink_request_pending_)
       HandlePendingCompositorFrameSinkRequest();
@@ -795,7 +799,7 @@ void CompositorImpl::InitializeDisplay(
                 nullptr, BrowserGpuMemoryBufferManager::current(),
                 viz::HostSharedBitmapManager::current());
 
-  display_->SetVisible(true);
+  display_->SetVisible(host_->IsVisible());
   display_->Resize(size_);
   host_->SetCompositorFrameSink(std::move(compositor_frame_sink));
 }