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base/native_library.h

Index: base/native_library.h
diff --git a/base/native_library.h b/base/native_library.h
index d7513d0b050e181b4df913e276b39051aef5318f..eac24d0e70937a0ba741275ea0e97b2de8a2d83c 100644
--- a/base/native_library.h
+++ b/base/native_library.h
@@ -8,6 +8,8 @@
 // This file defines a cross-platform "NativeLibrary" type which represents
 // a loadable module.
 
+#include <iosfwd>
+
 #include "base/base_export.h"
 #include "base/compiler_specific.h"
 #include "build/build_config.h"
@@ -50,11 +52,20 @@ typedef NativeLibraryStruct* NativeLibrary;
 typedef void* NativeLibrary;
 #endif  // OS_*
 
+struct NativeLibraryLoadError {
+#if defined(OS_WIN)
+  NativeLibraryLoadError() : code(0) {}
+  DWORD code;
+#else
+  std::string message;
+#endif  // OS_WIN
+};
+
 // Loads a native library from disk.  Release it with UnloadNativeLibrary when
 // you're done.  Returns NULL on failure.
-// If |error| is not NULL, it may be filled in with an error message on error.
+// If |error| is not NULL, it may be filled in on load error.
 BASE_EXPORT NativeLibrary LoadNativeLibrary(const FilePath& library_path,
-                                            std::string* error);
+                                            NativeLibraryLoadError* error);
 
 #if defined(OS_WIN)
 // Loads a native library from disk.  Release it with UnloadNativeLibrary when
@@ -79,6 +90,10 @@ BASE_EXPORT void* GetFunctionPointerFromNativeLibrary(NativeLibrary library,
 // "mylib.dylib" on Mac.
 BASE_EXPORT string16 GetNativeLibraryName(const string16& name);
 
+// Stream operator so NativeLibraryLoadError can be used in log statements.
+BASE_EXPORT std::ostream& operator<<(std::ostream& out,

[brettw, 2014/03/24 17:21:25]

The style guide permits operator<< for logging but says "you should try to avoid
these whenever possible". We do this for some of the very common classes we have
that need to be logged frequently. But in this case, it would seem to be just as
clear to add a GetError() member to the NativeLibraryLoadError that returns a
string that people can use for the log messages.

Then you can also remove the extra includes for ios stuff as well.

[xhwang, 2014/03/24 17:53:21]

Done.

+                                     const NativeLibraryLoadError& error);
+
 }  // namespace base
 
 #endif  // BASE_NATIVE_LIBRARY_H_