Replace OStream with std::ostream.

src/safepoint-table.h

Index: src/safepoint-table.h
diff --git a/src/safepoint-table.h b/src/safepoint-table.h
index 5fbfe419dbcb5667c44bd3457a694d4f29aa7aca..a7719e036d4552984bc49c09cb3aa9d437ca9198 100644
--- a/src/safepoint-table.h
+++ b/src/safepoint-table.h
@@ -104,7 +104,7 @@ class SafepointTable BASE_EMBEDDED {
   // Returns the entry for the given pc.
   SafepointEntry FindEntry(Address pc) const;
 
-  void PrintEntry(unsigned index, OStream& os) const;  // NOLINT
+  void PrintEntry(unsigned index, std::ostream& os) const;  // NOLINT
 
  private:
   static const uint8_t kNoRegisters = 0xFF;
@@ -127,7 +127,7 @@ class SafepointTable BASE_EMBEDDED {
     return GetPcOffsetLocation(index) + kPcSize;
   }
 
-  static void PrintBits(OStream& os,  // NOLINT
+  static void PrintBits(std::ostream& os,  // NOLINT
                         uint8_t byte, int digits);
 
   DisallowHeapAllocation no_allocation_;