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

content/ppapi_plugin/ppapi_broker_main.cc

Index: content/ppapi_plugin/ppapi_broker_main.cc
diff --git a/content/ppapi_plugin/ppapi_broker_main.cc b/content/ppapi_plugin/ppapi_broker_main.cc
index e2c6097b4a08fe8f12903632f367f1ec5f9d343d..956195b6d9441c9e090b20fd5bab74bad2b9ae8a 100644
--- a/content/ppapi_plugin/ppapi_broker_main.cc
+++ b/content/ppapi_plugin/ppapi_broker_main.cc
@@ -5,7 +5,8 @@
 #include "base/message_loop.h"
 #include "base/threading/platform_thread.h"
 #include "build/build_config.h"
-#include "content/common/child_process.h"
+#include "content/child/child_process.h"
+#include "content/common/debug_util.h"
 #include "content/ppapi_plugin/ppapi_thread.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/main_function_params.h"
@@ -16,7 +17,7 @@ namespace content {
 int PpapiBrokerMain(const MainFunctionParams& parameters) {
   const CommandLine& command_line = parameters.command_line;
   if (command_line.HasSwitch(switches::kPpapiStartupDialog)) {
-    ChildProcess::WaitForDebugger("PpapiBroker");
+    WaitForDebugger("PpapiBroker");
   }
 
   base::MessageLoop main_message_loop(base::MessageLoop::TYPE_DEFAULT);