Report PPAPI plugin load error code to UMA.

base/native_library_win.cc

 // 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.
 
 #include "base/native_library.h"
 
 #include <windows.h>
 
 #include "base/file_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_restrictions.h"
 
 namespace base {
 
 typedef HMODULE (WINAPI* LoadLibraryFunction)(const wchar_t* file_name);
 
 NativeLibrary LoadNativeLibraryHelper(const FilePath& library_path,
                                       LoadLibraryFunction load_library_api,
-                                      std::string* error) {
+                                      uint32* error_code) {
   // LoadLibrary() opens the file off disk.
   ThreadRestrictions::AssertIOAllowed();
 
   // Switch the current directory to the library directory as the library
   // may have dependencies on DLLs in this directory.
   bool restore_directory = false;
   FilePath current_directory;
   if (GetCurrentDirectory(&current_directory)) {
     FilePath plugin_path = library_path.DirName();
     if (!plugin_path.empty()) {
       SetCurrentDirectory(plugin_path);
       restore_directory = true;
     }
   }
 
   HMODULE module = (*load_library_api)(library_path.value().c_str());
-  if (!module && error) {
+  if (!module && error_code) {
     // GetLastError() needs to be called immediately after |load_library_api|.
-    DWORD last_error = GetLastError();
-    *error = StringPrintf("%u", last_error);
+    *error_code = GetLastError();
   }
 
   if (restore_directory)
     SetCurrentDirectory(current_directory);
 
   return module;
 }
 
 // static
 NativeLibrary LoadNativeLibrary(const FilePath& library_path,
-                                std::string* error) {
-  return LoadNativeLibraryHelper(library_path, LoadLibraryW, error);
+                                std::string* /* error_message */,

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

Shouldn't we try to be as consistent as possible (i.e. for log messages)?

if (!result)
  *error_message = StringPrintf();
return result;

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

Hmm, then the log message will be (error: 5 - 5) on Windows, which will be a bit
confusing.

[ddorwin, 2014/03/21 04:20:06]

Yes, but if you don't set it, callers that want an error message will need to
check for an empty message and format the error code themselves. Plus, this
behavior would probably need to be documented in the .h file.

I think it's more important to have consistent and expected behavior than to
worry about such a log message.

[xhwang, 2014/03/21 17:09:18]

Done.

+                                uint32* error_code) {
+  return LoadNativeLibraryHelper(library_path, LoadLibraryW, error_code);
 }
 
 NativeLibrary LoadNativeLibraryDynamically(const FilePath& library_path) {
   typedef HMODULE (WINAPI* LoadLibraryFunction)(const wchar_t* file_name);
 
   LoadLibraryFunction load_library;
   load_library = reinterpret_cast<LoadLibraryFunction>(
       GetProcAddress(GetModuleHandle(L"kernel32.dll"), "LoadLibraryW"));
 
   return LoadNativeLibraryHelper(library_path, load_library, NULL);
 }
 
 // static
 void UnloadNativeLibrary(NativeLibrary library) {
   FreeLibrary(library);
 }
 
 // static
 void* GetFunctionPointerFromNativeLibrary(NativeLibrary library,
                                           const char* name) {
   return GetProcAddress(library, name);
 }
 
 // static
 string16 GetNativeLibraryName(const string16& name) {
   return name + ASCIIToUTF16(".dll");
 }
 
 }  // namespace base