Support sideloaded fonts via command line option for blink layout_tests

content/shell/common/shell_switches.cc

Index: content/shell/common/shell_switches.cc
diff --git a/content/shell/common/shell_switches.cc b/content/shell/common/shell_switches.cc
index bd308b701a037e8203417fd50f292183e5d3fe0c..997981edb61df1eb53b58d485c17596a939de6c7 100644
--- a/content/shell/common/shell_switches.cc
+++ b/content/shell/common/shell_switches.cc
@@ -39,7 +39,12 @@ const char kEncodeBinary[] = "encode-binary";
 
 // Exposes the window.internals object to JavaScript for interactive development
 // and debugging of layout tests that rely on it.
-const char kExposeInternalsForTesting[]     = "expose-internals-for-testing";
+const char kExposeInternalsForTesting[] = "expose-internals-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";
 
 // This makes us disable some web-platform runtime features so that we test
 // content_shell as if it was a stable release. It is only followed when