Move a bunch of child-only code from content/common to content/child

content/plugin/plugin_main.cc

Index: content/plugin/plugin_main.cc
diff --git a/content/plugin/plugin_main.cc b/content/plugin/plugin_main.cc
index 298fbd4b5654fa8eea213656ce57ab3ca15c5dc3..78d7971e85338711300349d141a05974deb39a28 100644
--- a/content/plugin/plugin_main.cc
+++ b/content/plugin/plugin_main.cc
@@ -12,10 +12,11 @@
 #include "base/command_line.h"
 #include "base/hi_res_timer_manager.h"
 #include "base/message_loop.h"
-#include "base/string_util.h"
 #include "base/power_monitor/power_monitor.h"
+#include "base/string_util.h"
 #include "base/threading/platform_thread.h"
-#include "content/common/child_process.h"
+#include "content/child/child_process.h"
+#include "content/common/debug_util.h"
 #include "content/plugin/plugin_thread.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/main_function_params.h"
@@ -71,7 +72,7 @@ int PluginMain(const MainFunctionParams& parameters) {
 #endif
 
   if (parsed_command_line.HasSwitch(switches::kPluginStartupDialog)) {
-    ChildProcess::WaitForDebugger("Plugin");
+    WaitForDebugger("Plugin");
   }
 
   {