Fix CefCommandLine character case requirements (fixes issue #1872)

Switch names will now be converted to lowercase ASCII on all platforms.
Switch values will retain the original case and UTF8 encoding.

patch/patches/base_command_line_1872.patch

@@ -0,0 +1,17 @@
+diff --git base/command_line.cc base/command_line.cc
+index 3ef2e87e40687..f7b91a202a377 100644
+--- base/command_line.cc
++++ base/command_line.cc
+@@ -333,11 +333,10 @@ void CommandLine::AppendSwitchPath(StringPiece switch_string,
+ 
+ void CommandLine::AppendSwitchNative(StringPiece switch_string,
+                                      CommandLine::StringPieceType value) {
+-#if defined(OS_WIN)
+   const std::string switch_key = ToLowerASCII(switch_string);
++#if defined(OS_WIN)
+   StringType combined_switch_string(UTF8ToWide(switch_key));
+ #elif defined(OS_POSIX) || defined(OS_FUCHSIA)
+-  StringPiece switch_key = switch_string;
+   StringType combined_switch_string(switch_key);
+ #endif
+   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);