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

content/public/browser/content_browser_client.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_PUBLIC_BROWSER_CONTENT_BROWSER_CLIENT_H_
 #define CONTENT_PUBLIC_BROWSER_CONTENT_BROWSER_CLIENT_H_
 
 #include <map>
 #include <string>
 #include <utility>
@@ skipping 10 matching lines @@
 #include "content/public/common/media_stream_request.h"
 #include "content/public/common/permission_status.mojom.h"
 #include "content/public/common/resource_type.h"
 #include "content/public/common/socket_permission_request.h"
 #include "content/public/common/window_container_type.h"
 #include "net/base/mime_util.h"
 #include "net/cookies/canonical_cookie.h"
 #include "net/url_request/url_request_interceptor.h"
 #include "net/url_request/url_request_job_factory.h"
 #include "storage/browser/fileapi/file_system_context.h"
+#include "third_party/WebKit/public/platform/WebPageVisibilityState.h"
 #include "ui/base/window_open_disposition.h"
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 #include "base/posix/global_descriptors.h"
 #endif
 
 #if defined(OS_POSIX)
 #include "content/public/browser/file_descriptor_info.h"
 #endif
 
@@ skipping 547 matching lines @@
 
   // Allows to override browser Mojo services exposed through the
   // RenderProcessHost.
   virtual void OverrideRenderProcessMojoServices(ServiceRegistry* registry) {}
 
   // Registers additional navigator.connect service factories available in a
   // particular NavigatorConnectContext.
   virtual void GetAdditionalNavigatorConnectServices(
       const scoped_refptr<NavigatorConnectContext>& context) {}
 
+  // Allows to override the visibility state of a RenderFrameHost.
+  // |visibility_state| should not be null. It will only be set if needed.
+  virtual void OverridePageVisibilityState(
+      RenderFrameHost* render_frame_host,
+      blink::WebPageVisibilityState* visibility_state) {}
+
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
   // Populates |mappings| with all files that need to be mapped before launching
   // a child process.
   virtual void GetAdditionalMappedFilesForChildProcess(
       const base::CommandLine& command_line,
       int child_process_id,
       FileDescriptorInfo* mappings) {}
 #endif
 
 #if defined(OS_WIN)
@@ skipping 11 matching lines @@
   // Allows an embedder to provide its own ExternalVideoSurfaceContainer
   // implementation.  Return nullptr to disable external surface video.
   virtual ExternalVideoSurfaceContainer*
   OverrideCreateExternalVideoSurfaceContainer(WebContents* web_contents);
 #endif
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_CONTENT_BROWSER_CLIENT_H_