Report PPAPI plugin load error code to UMA.

base/native_library.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_NATIVE_LIBRARY_H_
 #define BASE_NATIVE_LIBRARY_H_
 
 // This file defines a cross-platform "NativeLibrary" type which represents
 // a loadable module.
 
+#include <string>
+
 #include "base/base_export.h"
 #include "base/compiler_specific.h"
+#include "base/strings/string16.h"
 #include "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #elif defined(OS_MACOSX)
 #import <CoreFoundation/CoreFoundation.h>
 #endif  // OS_*
 
-#include "base/strings/string16.h"
-
 namespace base {
 
 class FilePath;
 
 #if defined(OS_WIN)
 typedef HMODULE NativeLibrary;
 #elif defined(OS_MACOSX)
 enum NativeLibraryType {
   BUNDLE,
   DYNAMIC_LIB
@@ skipping 10 matching lines @@
   union {
     CFBundleRef bundle;
     void* dylib;
   };
 };
 typedef NativeLibraryStruct* NativeLibrary;
 #elif defined(OS_POSIX)
 typedef void* NativeLibrary;
 #endif  // OS_*
 
+struct BASE_EXPORT NativeLibraryLoadError {
+#if defined(OS_WIN)
+  NativeLibraryLoadError() : code(0) {}
+#endif  // OS_WIN
+
+  // Returns a string representation of the load error.
+  std::string ToString() const;
+
+#if defined(OS_WIN)
+  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
 // you're done.
 // This function retrieves the LoadLibrary function exported from kernel32.dll
 // and calls it instead of directly calling the LoadLibrary function via the
 // import table.
 BASE_EXPORT NativeLibrary LoadNativeLibraryDynamically(
     const FilePath& library_path);
 #endif  // OS_WIN
 
 // Unloads a native library.
 BASE_EXPORT void UnloadNativeLibrary(NativeLibrary library);
 
 // Gets a function pointer from a native library.
 BASE_EXPORT void* GetFunctionPointerFromNativeLibrary(NativeLibrary library,
                                                       const char* name);
 
 // Returns the full platform specific name for a native library.
 // For example:
 // "mylib" returns "mylib.dll" on Windows, "libmylib.so" on Linux,
 // "mylib.dylib" on Mac.
 BASE_EXPORT string16 GetNativeLibraryName(const string16& name);
 
 }  // namespace base
 
 #endif  // BASE_NATIVE_LIBRARY_H_