Move platform abstraction to base library

src/heap-snapshot-generator.cc

Index: src/heap-snapshot-generator.cc
diff --git a/src/heap-snapshot-generator.cc b/src/heap-snapshot-generator.cc
index be970eeeeb3c19bcdccb59f02eba2ecc6a187873..097d5a5fc57968df0cbb01930002257b1bf408ae 100644
--- a/src/heap-snapshot-generator.cc
+++ b/src/heap-snapshot-generator.cc
@@ -83,21 +83,21 @@ void HeapEntry::SetIndexedReference(HeapGraphEdge::Type type,
 void HeapEntry::Print(
     const char* prefix, const char* edge_name, int max_depth, int indent) {
   STATIC_ASSERT(sizeof(unsigned) == sizeof(id()));
-  OS::Print("%6" V8PRIuPTR " @%6u %*c %s%s: ",
-            self_size(), id(), indent, ' ', prefix, edge_name);
+  base::OS::Print("%6" V8PRIuPTR " @%6u %*c %s%s: ", self_size(), id(), indent,
+                  ' ', prefix, edge_name);
   if (type() != kString) {
-    OS::Print("%s %.40s\n", TypeAsString(), name_);
+    base::OS::Print("%s %.40s\n", TypeAsString(), name_);
   } else {
-    OS::Print("\"");
+    base::OS::Print("\"");
     const char* c = name_;
     while (*c && (c - name_) <= 40) {
       if (*c != '\n')
-        OS::Print("%c", *c);
+        base::OS::Print("%c", *c);
       else
-        OS::Print("\\n");
+        base::OS::Print("\\n");
       ++c;
     }
-    OS::Print("\"\n");
+    base::OS::Print("\"\n");
   }
   if (--max_depth == 0) return;
   Vector<HeapGraphEdge*> ch = children();