Revert r12625 due to sandbox incompatibility.

src/platform-linux.cc

Index: src/platform-linux.cc
diff --git a/src/platform-linux.cc b/src/platform-linux.cc
index f934da1c751c820cae5f4208f664cba6ae9058e5..606d10236eb5f6a498eda7034b609edd56974d7a 100644
--- a/src/platform-linux.cc
+++ b/src/platform-linux.cc
@@ -701,24 +701,6 @@ bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
 }
 
 
-bool VirtualMemory::CommittedPhysicalSizeInRegion(
-    void* base, size_t size, size_t* physical) {
-  const size_t page_size = sysconf(_SC_PAGESIZE);
-  base = reinterpret_cast<void*>(
-      reinterpret_cast<intptr_t>(base) & ~(page_size - 1));
-  const size_t pages = (size + page_size - 1) / page_size;
-  ScopedVector<unsigned char> buffer(pages);
-  int result = mincore(base, size, buffer.start());
-  if (result) return false;
-  int resident_pages = 0;
-  for (unsigned i = 0; i < pages; ++i) {
-    resident_pages += buffer[i] & 1;
-  }
-  *physical = resident_pages * page_size;
-  return true;
-}
-
-
 class Thread::PlatformData : public Malloced {
  public:
   PlatformData() : thread_(kNoThread) {}