Remove command line flag --disable-plugins

BUG=366349

Review URL: https://codereview.chromium.org/829133009

Cr-Commit-Position: refs/heads/master@{#311475}

chromecast/browser/cast_browser_main_parts.cc

@@ -93,7 +93,6 @@ DefaultCommandLineSwitch g_default_switches[] = {
   { switches::kDisableGestureRequirementForMediaPlayback, ""},
   { switches::kForceUseOverlayEmbeddedVideo, ""},
 #endif
-  { switches::kDisablePlugins, "" },
   // Always enable HTMLMediaElement logs.
   { switches::kBlinkPlatformLogChannels, "Media"},
 #if defined(DISABLE_DISPLAY)

content/browser/renderer_host/render_view_host_impl.cc

@@ -327,8 +327,6 @@ WebPreferences RenderViewHostImpl::ComputeWebkitPrefs(const GURL& url) {
 
   prefs.web_security_enabled =
       !command_line.HasSwitch(switches::kDisableWebSecurity);
-  prefs.plugins_enabled =
-      !command_line.HasSwitch(switches::kDisablePlugins);
   prefs.java_enabled =
       !command_line.HasSwitch(switches::kDisableJava);
 

content/public/common/content_switches.cc

@@ -199,9 +199,6 @@ const char kDisablePepper3d[]               = "disable-pepper-3d";
 // Disables compositor-accelerated touch-screen pinch gestures.
 const char kDisablePinch[]                  = "disable-pinch";
 
-// Prevent plugins from running.
-const char kDisablePlugins[]                = "disable-plugins";
-
 // Disable discovering third-party plug-ins. Effectively loading only
 // ones shipped with the browser plus third-party ones as specified by
 // --extra-plugin-dir and --load-plugin switches.

content/public/common/content_switches.h

@@ -67,7 +67,6 @@ CONTENT_EXPORT extern const char kDisableMediaSource[];
 CONTENT_EXPORT extern const char kDisableOneCopy[];
 extern const char kDisablePepper3d[];
 CONTENT_EXPORT extern const char kDisablePinch[];
-CONTENT_EXPORT extern const char kDisablePlugins[];
 CONTENT_EXPORT extern const char kDisablePluginsDiscovery[];
 extern const char kDisableRemoteFonts[];
 extern const char kDisableRendererAccessibility[];