Move Pickle to base namespace.

content/browser/zygote_host/zygote_host_impl_linux.h

Index: content/browser/zygote_host/zygote_host_impl_linux.h
diff --git a/content/browser/zygote_host/zygote_host_impl_linux.h b/content/browser/zygote_host/zygote_host_impl_linux.h
index 643989f07eee2e13b11f84729666733088979d13..c8bae9512b9f6d5feb5d857b89929890cd4b4ccb 100644
--- a/content/browser/zygote_host/zygote_host_impl_linux.h
+++ b/content/browser/zygote_host/zygote_host_impl_linux.h
@@ -78,7 +78,7 @@ class CONTENT_EXPORT ZygoteHostImpl : public ZygoteHost {
   // Sends |data| to the zygote via |control_fd_|.  If |fds| is non-NULL, the
   // included file descriptors will also be passed.  The caller is responsible
   // for acquiring |control_lock_|.
-  bool SendMessage(const Pickle& data, const std::vector<int>* fds);
+  bool SendMessage(const base::Pickle& data, const std::vector<int>* fds);
 
   ssize_t ReadReply(void* buf, size_t buflen);