Remove socket.h include from debug.h

Looks like there is no Socket usage in debug.h, so we don't need to
include it there.

TEST=in static build, ninja -C out/Debug/ d8
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/120933003

Patch from Thiago Farina <tfarina@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18459 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/d8-debug.cc

@@ -30,6 +30,7 @@
 #include "d8.h"
 #include "d8-debug.h"
 #include "debug-agent.h"
+#include "platform/socket.h"
 
 
 namespace v8 {

src/debug.h

@@ -38,7 +38,6 @@
 #include "frames-inl.h"
 #include "hashmap.h"
 #include "platform.h"
-#include "platform/socket.h"
 #include "string-stream.h"
 #include "v8threads.h"