Fix "unreachable code" warnings (MSVC warning 4702) in net/.

net/disk_cache/simple/simple_util.cc

Index: net/disk_cache/simple/simple_util.cc
===================================================================
--- net/disk_cache/simple/simple_util.cc	(revision 257821)
+++ net/disk_cache/simple/simple_util.cc	(working copy)
@@ -28,16 +28,18 @@
 #if defined(OS_ANDROID)
   *out_sec = st.st_mtime;
   *out_nsec = st.st_mtime_nsec;
+  return true;
 #elif defined(OS_LINUX)
   *out_sec = st.st_mtim.tv_sec;
   *out_nsec = st.st_mtim.tv_nsec;
+  return true;
 #elif defined(OS_MACOSX) || defined(OS_IOS) || defined(OS_BSD)
   *out_sec = st.st_mtimespec.tv_sec;
   *out_nsec = st.st_mtimespec.tv_nsec;
+  return true;
 #else
   return false;
 #endif
-  return true;
 }
 
 }  // namespace