Remove file name from File C++ structure. It is not used.

runtime/bin/file.h

Index: runtime/bin/file.h
diff --git a/runtime/bin/file.h b/runtime/bin/file.h
index 7b6ea8c09653b584d514c9a6f90fcf36de2a84fb..50ad3b4efc1fd363b2d924a55bbdde656000aea6 100644
--- a/runtime/bin/file.h
+++ b/runtime/bin/file.h
@@ -109,8 +109,6 @@ class File {
   // Returns whether the file has been closed.
   bool IsClosed();
 
-  const char* name() const { return name_; }
-
   // Open the file with the given name. The file is always opened for
   // reading. If mode contains kWrite the file is opened for both
   // reading and writing. If mode contains kWrite and the file does
@@ -139,12 +137,11 @@ class File {
   static Dart_Port GetServicePort();
 
  private:
-  File(const char* name, FileHandle* handle) : name_(name), handle_(handle) { }
+  explicit File(FileHandle* handle) : handle_(handle) { }
   void Close();
 
   static const int kClosedFd = -1;
 
-  const char* name_;
   // FileHandle is an OS specific class which stores data about the file.
   FileHandle* handle_;  // OS specific handle for the file.