Revert r12625 due to sandbox incompatibility.

src/platform-openbsd.cc

Index: src/platform-openbsd.cc
diff --git a/src/platform-openbsd.cc b/src/platform-openbsd.cc
index 558361dbad15afc795113a2027bd751535efb2df..408d4dc0f8487e08a8a4277ad8139f4910b6d4de 100644
--- a/src/platform-openbsd.cc
+++ b/src/platform-openbsd.cc
@@ -504,13 +504,6 @@ bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
 }
 
 
-bool VirtualMemory::CommittedPhysicalSizeInRegion(
-    void* base, size_t size, size_t* physical) {
-  // TODO(alph): implement for the platform.
-  return false;
-}
-
-
 class Thread::PlatformData : public Malloced {
  public:
   PlatformData() : thread_(kNoThread) {}