Replace OStream with std::ostream.

src/safepoint-table.cc

Index: src/safepoint-table.cc
diff --git a/src/safepoint-table.cc b/src/safepoint-table.cc
index 89500e2047a6949accd168a38f42d1960131de4f..aaa32b9e145ca5b90ff85c69f6e7ec5f5500b3b6 100644
--- a/src/safepoint-table.cc
+++ b/src/safepoint-table.cc
@@ -61,7 +61,8 @@ SafepointEntry SafepointTable::FindEntry(Address pc) const {
 }
 
 
-void SafepointTable::PrintEntry(unsigned index, OStream& os) const {  // NOLINT
+void SafepointTable::PrintEntry(unsigned index,
+                                std::ostream& os) const {  // NOLINT
   disasm::NameConverter converter;
   SafepointEntry entry = GetEntry(index);
   uint8_t* bits = entry.bits();
@@ -86,7 +87,7 @@ void SafepointTable::PrintEntry(unsigned index, OStream& os) const {  // NOLINT
 }
 
 
-void SafepointTable::PrintBits(OStream& os,  // NOLINT
+void SafepointTable::PrintBits(std::ostream& os,  // NOLINT
                                uint8_t byte, int digits) {
   DCHECK(digits >= 0 && digits <= kBitsPerByte);
   for (int i = 0; i < digits; i++) {