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

content/gpu/gpu_watchdog_thread.h

Index: content/gpu/gpu_watchdog_thread.h
===================================================================
--- content/gpu/gpu_watchdog_thread.h	(revision 163290)
+++ content/gpu/gpu_watchdog_thread.h	(working copy)
@@ -12,6 +12,8 @@
 #include "base/time.h"
 #include "content/common/gpu/gpu_watchdog.h"
 
+namespace content {
+
 // A thread that intermitently sends tasks to a group of watched message loops
 // and deliberately crashes if one of them does not respond after a timeout.
 class GpuWatchdogThread : public base::Thread,
@@ -76,4 +78,6 @@
   DISALLOW_COPY_AND_ASSIGN(GpuWatchdogThread);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_GPU_GPU_WATCHDOG_THREAD_H_