Revert of Revert some other possible suspects of a 0.43% size increase of setup.exe: https://build.chromium.o…

base/files/file.h

Index: base/files/file.h
diff --git a/base/files/file.h b/base/files/file.h
index 89077b41c1d8d03a9aa1e33ea822b9fb9454f807..589403d8dbf9efbd0dbc00a18278df9ea7e035a4 100644
--- a/base/files/file.h
+++ b/base/files/file.h
@@ -18,6 +18,7 @@
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
+#include "base/files/file_path.h"
 #include "base/files/scoped_file.h"
 #include "base/gtest_prod_util.h"
 #include "base/move.h"
@@ -30,8 +31,6 @@
 FORWARD_DECLARE_TEST(FileTest, MemoryCorruption);
 
 namespace base {
-
-class FilePath;
 
 #if defined(OS_WIN)
 typedef HANDLE PlatformFile;
@@ -162,8 +161,8 @@
   File();
 
   // Creates or opens the given file. This will fail with 'access denied' if the
-  // |name| contains path traversal ('..') components.
-  File(const FilePath& name, uint32 flags);
+  // |path| contains path traversal ('..') components.
+  File(const FilePath& path, uint32 flags);
 
   // Takes ownership of |platform_file|.
   explicit File(PlatformFile platform_file);
@@ -180,7 +179,7 @@
   File& operator=(RValue other);
 
   // Creates or opens the given file.
-  void Initialize(const FilePath& name, uint32 flags);
+  void Initialize(const FilePath& path, uint32 flags);
 
   bool IsValid() const;
 
@@ -191,7 +190,7 @@
 
   // Returns the OS result of opening this file. Note that the way to verify
   // the success of the operation is to use IsValid(), not this method:
-  //   File file(name, flags);
+  //   File file(path, flags);
   //   if (!file.IsValid())
   //     return;
   Error error_details() const { return error_details_; }
@@ -305,6 +304,8 @@
  private:
   FRIEND_TEST_ALL_PREFIXES(::FileTest, MemoryCorruption);
 
+  friend class ScopedFileTrace;
+
 #if defined(OS_POSIX)
   // Encloses a single ScopedFD, saving a cheap tamper resistent memory checksum
   // alongside it. This checksum is validated at every access, allowing early
@@ -350,9 +351,9 @@
   };
 #endif
 
-  // Creates or opens the given file. Only called if |name| has no traversal
-  // ('..') components.
-  void DoInitialize(const FilePath& name, uint32 flags);
+  // Creates or opens the given file. Only called if |path_| has no
+  // traversal ('..') components.
+  void DoInitialize(uint32 flags);
 
   // TODO(tnagel): Reintegrate into Flush() once histogram isn't needed anymore,
   // cf. issue 473337.
@@ -365,6 +366,18 @@
 #elif defined(OS_POSIX)
   MemoryCheckingScopedFD file_;
 #endif
+
+  // Path that |Initialize()| was called with. Only set if safe (i.e. no '..').
+  FilePath path_;
+
+  class TraceEnabler {
+   public:
+    TraceEnabler();
+    ~TraceEnabler();
+  };
+
+  // Object tied to the lifetime of this File that enables/disables tracing.
+  TraceEnabler trace_enabler_;
 
   Error error_details_;
   bool created_;