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..77a5502cce8cdaa11926eb3ff758d99ad041858e 100644
--- a/base/native_library_win.cc
+++ b/base/native_library_win.cc
@@ -4,6 +4,8 @@
 
 #include "base/native_library.h"
 
+#include <ostream>
+
 #include <windows.h>
 
 #include "base/file_util.h"
@@ -15,9 +17,11 @@ namespace base {
 
 typedef HMODULE (WINAPI* LoadLibraryFunction)(const wchar_t* file_name);
 
+namespace {
+
 NativeLibrary LoadNativeLibraryHelper(const FilePath& library_path,
                                       LoadLibraryFunction load_library_api,
-                                      std::string* error) {
+                                      NativeLibraryLoadError* error) {
   // LoadLibrary() opens the file off disk.
   ThreadRestrictions::AssertIOAllowed();
 
@@ -36,8 +40,7 @@ NativeLibrary LoadNativeLibraryHelper(const FilePath& library_path,
   HMODULE module = (*load_library_api)(library_path.value().c_str());
   if (!module && error) {
     // 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)
@@ -46,9 +49,11 @@ NativeLibrary LoadNativeLibraryHelper(const FilePath& library_path,
   return module;
 }
 
+}  // namespace
+
 // static
 NativeLibrary LoadNativeLibrary(const FilePath& library_path,
-                                std::string* error) {
+                                NativeLibraryLoadError* error) {
   return LoadNativeLibraryHelper(library_path, LoadLibraryW, error);
 }
 
@@ -78,4 +83,10 @@ string16 GetNativeLibraryName(const string16& name) {
   return name + ASCIIToUTF16(".dll");
 }
 
+// static
+std::ostream& operator<<(std::ostream& out,
+                         const NativeLibraryLoadError& error) {
+  return out << error.code;
+}
+
 }  // namespace base