Move a bunch of code in content\common (as well as a few left in renderer) to the content namespace.

content/common/child_process.cc

Index: content/common/child_process.cc
===================================================================
--- content/common/child_process.cc	(revision 163290)
+++ content/common/child_process.cc	(working copy)
@@ -24,6 +24,8 @@
 static void SigUSR1Handler(int signal) { }
 #endif
 
+namespace content {
+
 ChildProcess* ChildProcess::child_process_;
 
 ChildProcess::ChildProcess()
@@ -124,3 +126,5 @@
 #endif  // defined(OS_ANDROID)
 #endif  // defined(OS_POSIX)
 }
+
+}  // namespace content