Use kRenderClientId command line flag when starting a render process

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 20eeefc2376664b5dd310e2c2421666eebcdb8f7..a13d9fcd2e025383b5f9b827631f58e0f3eaa251 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -748,6 +748,8 @@ const char kRegisterPepperPlugins[]         = "register-pepper-plugins";
 // Enables remote debug over HTTP on the specified port.
 const char kRemoteDebuggingPort[]           = "remote-debugging-port";
 
+const char kRendererClientId[] = "renderer-client-id";
+
 // The contents of this flag are prepended to the renderer command line.
 // Useful values might be "valgrind" or "xterm -e gdb --args".
 const char kRendererCmdPrefix[]             = "renderer-cmd-prefix";