Make Page Visibility API work when the browser window is visible or not

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index c9cbd6689944fbccc878e9e79f505e7f256630e5..e07114c4d06c59674f77383aea60ce3100ee57f9 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -1326,6 +1326,7 @@ bool RenderViewImpl::OnMessageReceived(const IPC::Message& message) {
                         OnReleaseDisambiguationPopupBitmap)
     IPC_MESSAGE_HANDLER(ViewMsg_ForceRedraw, OnForceRedraw)
     IPC_MESSAGE_HANDLER(ViewMsg_SelectWordAroundCaret, OnSelectWordAroundCaret)
+    IPC_MESSAGE_HANDLER(ViewMsg_SetWindowVisibility, OnSetWindowVisibility)
 #if defined(OS_ANDROID)
     IPC_MESSAGE_HANDLER(InputMsg_ActivateNearestFindResult,
                         OnActivateNearestFindResult)
@@ -1339,7 +1340,6 @@ bool RenderViewImpl::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(ViewMsg_PluginImeCompositionCompleted,
                         OnPluginImeCompositionCompleted)
     IPC_MESSAGE_HANDLER(ViewMsg_SetInLiveResize, OnSetInLiveResize)
-    IPC_MESSAGE_HANDLER(ViewMsg_SetWindowVisibility, OnSetWindowVisibility)
     IPC_MESSAGE_HANDLER(ViewMsg_WindowFrameChanged, OnWindowFrameChanged)
 #endif
     // Adding a new message? Add platform independent ones first, then put the
@@ -3016,8 +3016,8 @@ void RenderViewImpl::OnSetActive(bool active) {
 #endif
 }
 
-#if defined(OS_MACOSX)
 void RenderViewImpl::OnSetWindowVisibility(bool visible) {
+#if defined(OS_MACOSX)
 #if defined(ENABLE_PLUGINS)
   // Inform plugins that their container has changed visibility.
   std::set<WebPluginDelegateProxy*>::iterator plugin_it;
@@ -3026,8 +3026,15 @@ void RenderViewImpl::OnSetWindowVisibility(bool visible) {
     (*plugin_it)->SetContainerVisibility(visible);
   }
 #endif
+#else
+  if (webview())
+    webview()->setVisibilityState(visible ?
+        blink::WebPageVisibilityStateVisible :
+        blink::WebPageVisibilityStateHidden, false);
+#endif
 }
 
+#if defined(OS_MACOSX)
 void RenderViewImpl::OnWindowFrameChanged(const gfx::Rect& window_frame,
                                           const gfx::Rect& view_frame) {
 #if defined(ENABLE_PLUGINS)