Expose the visibility state of a frame to the browser process.

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index f183f91cc765774be96018d7bf11cfbc1ed2c4cb..7447abb9f062b62bd0556cc0994803d1a125dbc6 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -2610,6 +2610,25 @@ ChromeContentBrowserClient::OverrideCookieStoreForRenderProcess(
                                  render_process_id).get();
 }
 
+void ChromeContentBrowserClient::OverridePageVisibilityState(
+      RenderFrameHost* render_frame_host,
+      blink::WebPageVisibilityState* visibility_state) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  WebContents* web_contents =
+      WebContents::FromRenderFrameHost(render_frame_host);
+  DCHECK(web_contents);
+
+  Profile* profile =
+      Profile::FromBrowserContext(web_contents->GetBrowserContext());
+  prerender::PrerenderManager* prerender_manager =
+      prerender::PrerenderManagerFactory::GetForProfile(profile);
+  if (prerender_manager &&
+      prerender_manager->IsWebContentsPrerendering(web_contents, nullptr)) {
+    *visibility_state = blink::WebPageVisibilityStatePrerender;
+  }
+}
+
 #if defined(ENABLE_WEBRTC)
 void ChromeContentBrowserClient::MaybeCopyDisableWebRtcEncryptionSwitch(
     base::CommandLine* to_command_line,