Remove pageVisibility option

The original purpose of this option is not working anymore, also adds
docs on the current way to disable process backgrounding.

atom/browser/web_contents_preferences.cc

@@ -34,8 +34,6 @@ FeaturePair kWebRuntimeFeatures[] = {
     switches::kExperimentalFeatures },
   { options::kExperimentalCanvasFeatures,
     switches::kExperimentalCanvasFeatures },
-  { options::kPageVisibility,
-    switches::kPageVisibility },
 };
 
 }  // namespace

atom/common/options_switches.cc

@@ -85,9 +85,6 @@ const char kNodeIntegration[] = "nodeIntegration";
 // Instancd ID of guest WebContents.
 const char kGuestInstanceID[] = "guestInstanceId";
 
-// Set page visiblity to always visible.
-const char kPageVisibility[] = "pageVisibility";
-
 // Enable DirectWrite on Windows.
 const char kDirectWrite[] = "directWrite";
 
@@ -141,7 +138,6 @@ const char kNodeIntegration[]            = "node-integration";
 const char kGuestInstanceID[]            = "guest-instance-id";
 const char kExperimentalFeatures[]       = "experimental-features";
 const char kExperimentalCanvasFeatures[] = "experimental-canvas-features";
-const char kPageVisibility[]             = "page-visiblity";
 const char kOpenerID[]                   = "opener-id";
 
 // Widevine options

atom/common/options_switches.h

@@ -49,7 +49,6 @@ extern const char kNodeIntegration[];
 extern const char kGuestInstanceID[];
 extern const char kExperimentalFeatures[];
 extern const char kExperimentalCanvasFeatures[];
-extern const char kPageVisibility[];
 extern const char kOpenerID[];
 
 }   // namespace options
@@ -77,7 +76,6 @@ extern const char kNodeIntegration[];
 extern const char kGuestInstanceID[];
 extern const char kExperimentalFeatures[];
 extern const char kExperimentalCanvasFeatures[];
-extern const char kPageVisibility[];
 extern const char kOpenerID[];
 
 extern const char kWidevineCdmPath[];

atom/renderer/atom_renderer_client.cc

@@ -210,19 +210,6 @@ content::BrowserPluginDelegate* AtomRendererClient::CreateBrowserPluginDelegate(
   }
 }
 
-bool AtomRendererClient::ShouldOverridePageVisibilityState(
-    const content::RenderFrame* render_frame,
-    blink::WebPageVisibilityState* override_state) {
-  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
-
-  if (IsSwitchEnabled(command_line, switches::kPageVisibility)) {
-    *override_state = blink::WebPageVisibilityStateVisible;
-    return true;
-  }
-
-  return false;
-}
-
 void AtomRendererClient::EnableWebRuntimeFeatures() {
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
 

atom/renderer/atom_renderer_client.h

@@ -56,9 +56,6 @@ class AtomRendererClient : public content::ContentRendererClient,
       content::RenderFrame* render_frame,
       const std::string& mime_type,
       const GURL& original_url) override;
-  bool ShouldOverridePageVisibilityState(
-      const content::RenderFrame* render_frame,
-      blink::WebPageVisibilityState* override_state) override;
   void AddKeySystems(std::vector<media::KeySystemInfo>* key_systems) override;
 
   void EnableWebRuntimeFeatures();

docs/api/browser-window.md

@@ -138,10 +138,6 @@ It creates a new `BrowserWindow` with native properties as set by the `options`.
     canvas features. Default is `false`.
   * `directWrite` Boolean - Enables DirectWrite font rendering system on
      Windows. Default is `true`.
-  * `pageVisibility` Boolean - Page would be forced to be always in visible
-     or hidden state once set, instead of reflecting current window's
-     visibility. Users can set it to `true` to prevent throttling of DOM
-     timers. Default is `false`.
 
 ## Events
 

docs/api/chrome-command-line-switches.md

@@ -94,10 +94,6 @@ connection, and the endpoint host in a `SOCKS` proxy connection).
 
 Like `--host-rules` but these `rules` only apply to the host resolver.
 
-[app]: app.md
-[append-switch]: app.md#appcommandlineappendswitchswitch-value
-[ready]: app.md#event-ready
-
 ## --ignore-certificate-errors
 
 Ignores certificate related errors.
@@ -121,7 +117,16 @@ fallback will accept.
 
 ## --cipher-suite-blacklist=`cipher_suites`
 
-Specify comma-separated list of SSL cipher suites to disable.
+Specifies comma-separated list of SSL cipher suites to disable.
+
+## --disable-renderer-backgrounding
+
+Prevents Chromium from lowering the priority of invisible pages' renderer
+processes.
+
+This flag is global to all renderer processes, if you only want to disable
+throttling in one window, you can take the hack of
+[playing silent audio][play-silent-audio].
 
 ## --enable-logging
 
@@ -149,3 +154,8 @@ whole pathname and not just the module. E.g. `*/foo/bar/*=2` would change the
 logging level for all code in the source files under a `foo/bar` directory.
 
 This switch only works when `--enable-logging` is also passed.
+
+[app]: app.md
+[append-switch]: app.md#appcommandlineappendswitchswitch-value
+[ready]: app.md#event-ready
+[play-silent-audio]: https://github.com/atom/atom/pull/9485/files