Report PPAPI plugin load error code to UMA.

base/native_library.h

Index: base/native_library.h
diff --git a/base/native_library.h b/base/native_library.h
index d7513d0b050e181b4df913e276b39051aef5318f..51105492794b70191f7f92ce16fe446b17ed21f1 100644
--- a/base/native_library.h
+++ b/base/native_library.h
@@ -54,7 +54,8 @@ typedef void* NativeLibrary;
 // you're done.  Returns NULL on failure.
 // If |error| is not NULL, it may be filled in with an error message on error.

[ddorwin, 2014/03/20 22:01:12]

Similar comment for error_code. We might specifically mention "if the platform
supports it."

[xhwang, 2014/03/21 01:42:58]

Done.

 BASE_EXPORT NativeLibrary LoadNativeLibrary(const FilePath& library_path,
-                                            std::string* error);
+                                            std::string* error_message,
+                                            uint32* error_code = NULL);

[xhwang, 2014/03/20 21:40:03]

This optional parameter is just trying to avoid update all other call sites
(>10) in this prototype CL. I'll either update all call sites with NULL
|error_code|, or add a new function in this file, e.g.
LoadNativeLibraryAndReportError(). Let me know which one you prefer.

 
 #if defined(OS_WIN)
 // Loads a native library from disk.  Release it with UnloadNativeLibrary when