Remove the MSAA WebSetting, which is not read or used.

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 164f77f1edd3b7df7a5279097b36a4144bc92290..5ee7bd6bd1fad4c3521a02667995be0daef965e7 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -944,9 +944,6 @@ void RenderView::ApplyWebPreferences(const WebPreferences& prefs,
   // and support is compiled in.
   settings->setExperimentalWebGLEnabled(prefs.experimental_webgl_enabled);
 
-  // Disable GL multisampling if requested on command line.
-  settings->setOpenGLMultisamplingEnabled(prefs.gl_multisampling_enabled);
-
   // Enable WebGL errors to the JS console if requested.
   settings->setWebGLErrorsToConsoleEnabled(
       prefs.webgl_errors_to_console_enabled);