Remove shared worker process related codes.

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 1bc2a24ca3067f847094961ecf561f2dc2ac01be..a9cf52f16e17f45b11ab9fca00d73c04f98dc21a 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -851,9 +851,6 @@ const char kValidateInputEventStream[] = "validate-input-event-stream";
 // kWaitForDebugger flag passed on or not.
 const char kWaitForDebuggerChildren[]       = "wait-for-debugger-children";
 
-// Causes the process to run as a worker subprocess.
-const char kWorkerProcess[]                 = "worker";
-
 // The prefix used when starting the zygote process. (i.e. 'gdb --args')
 const char kZygoteCmdPrefix[]               = "zygote-cmd-prefix";