Report PPAPI plugin load error code to UMA.

base/native_library_win.cc

Index: base/native_library_win.cc
diff --git a/base/native_library_win.cc b/base/native_library_win.cc
index bcea485a1d10582016622738f1081fde471cd567..f78c0c23fc7e34d9aa49e45e3f3b3eb983fdedaa 100644
--- a/base/native_library_win.cc
+++ b/base/native_library_win.cc
@@ -17,7 +17,7 @@ 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();
 
@@ -34,10 +34,9 @@ NativeLibrary LoadNativeLibraryHelper(const FilePath& library_path,
   }
 
   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)
@@ -48,8 +47,9 @@ NativeLibrary LoadNativeLibraryHelper(const FilePath& library_path,
 
 // 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) {