Update to Chromium version 88.0.4324.0 (#827102)

- Mac: Xcode 12.2 and the MacOS 11.0 SDK are now required for building.
- MacOS 10.10 (Yosemite) is no longer supported (see https://crbug.com/1126056).
- Flash is no longer supported (see https://www.chromium.org/flash-roadmap).

include/cef_web_plugin.h

@@ -48,7 +48,7 @@ class CefBrowser;
 class CefWebPluginInfo : public virtual CefBaseRefCounted {
  public:
   ///
-  // Returns the plugin name (i.e. Flash).
+  // Returns the plugin name.
   ///
   /*--cef()--*/
   virtual CefString GetName() = 0;