Specify AllowCaching = false for some ChromeOS UI pages

chrome/browser/ui/webui/chromeos/proxy_settings_ui.cc

Index: chrome/browser/ui/webui/chromeos/proxy_settings_ui.cc
diff --git a/chrome/browser/ui/webui/chromeos/proxy_settings_ui.cc b/chrome/browser/ui/webui/chromeos/proxy_settings_ui.cc
index a6bd8860d54347f01153bfc962688073eda1895f..6a1c0b4db82dafb448df894a582022bcce09b68e 100644
--- a/chrome/browser/ui/webui/chromeos/proxy_settings_ui.cc
+++ b/chrome/browser/ui/webui/chromeos/proxy_settings_ui.cc
@@ -46,6 +46,11 @@ class ProxySettingsHTMLSource : public content::URLDataSource {
     return "text/html";
   }
   bool ShouldAddContentSecurityPolicy() const override { return false; }
+  bool AllowCaching() const override {
+    // Should not be cached to reflect dynamically-generated contents that
+    // may depend on current settings.
+    return false;
+  }
 
  protected:
   ~ProxySettingsHTMLSource() override {}