Support sideloaded fonts via command line option for blink layout_tests

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 37d2cd4b251882918ceff9fc06d889fbd7e523ac..e9c0f71d292bc4ba16979b558de93dfe852c4788 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -779,6 +779,11 @@ const char kProcessType[]                   = "type";
 // for testing purposes only.
 const char kReduceSecurityForTesting[]      = "reduce-security-for-testing";
 
+ // Registers additional font files on Windows (for fonts outside the usual
+// %WINDIR%\Fonts location). Multiple files can be used by separating them
+// with a semicolon (;).
+const char kRegisterFontFiles[]             = "register-font-files";
+
 // Register Pepper plugins (see pepper_plugin_list.cc for its format).
 const char kRegisterPepperPlugins[]         = "register-pepper-plugins";