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,

[ddorwin, 2014/03/21 17:24:59]

Not related to this CL, but this should be static/anonymous.

[xhwang, 2014/03/21 19:00:54]

Done.

                                       LoadLibraryFunction load_library_api,
-                                      std::string* error) {
+                                      std::string* error_message,
+                                      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) {

[ddorwin, 2014/03/21 17:24:59]

This should be "...&& (error_code || error_message)" - or maybe something else
depending on the outcome below.

You'll then need to check error_code at ine 42.

[xhwang, 2014/03/21 19:00:54]

Now this is obsolete.

     // GetLastError() needs to be called immediately after |load_library_api|.
     DWORD last_error = GetLastError();
-    *error = StringPrintf("%u", last_error);
+    *error_message = StringPrintf("%u", last_error);

[ddorwin, 2014/03/21 17:24:59]

You need to check for a NULL error_message.

Actually, since we just convert the error code to a string and one of the
callers doesn't want this, I was thinking this could be done in the public
function. That makes the function slightly more complex, but it keeps the
responsibilities of this one to a minimum. WDYT?

OTOH, it's possible that error_code was not passed to the public function, so
you'd need to create a local variable to get it out, so maybe doing it here is
better.

[xhwang, 2014/03/21 19:00:54]

I think the new NativeLibraryLoadError helps avoid all these issues. WDYT?

+    *error_code = last_error;
   }
 
   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,
+                                uint32* error_code) {
+  return LoadNativeLibraryHelper(
+      library_path, LoadLibraryW, error_message, 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);
+  return LoadNativeLibraryHelper(library_path, load_library, NULL, 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