Report PPAPI plugin load error code to UMA.

base/native_library_posix.cc

Index: base/native_library_posix.cc
diff --git a/base/native_library_posix.cc b/base/native_library_posix.cc
index dfa20fc01cf78ef6ab2061f3eefb32d3c8f324c0..256a651edd6cce9b1cb63983fa304521a974472f 100644
--- a/base/native_library_posix.cc
+++ b/base/native_library_posix.cc
@@ -4,6 +4,8 @@
 
 #include "base/native_library.h"
 
+#include <ostream>
+
 #include <dlfcn.h>
 
 #include "base/files/file_path.h"
@@ -15,7 +17,7 @@ namespace base {
 
 // static
 NativeLibrary LoadNativeLibrary(const FilePath& library_path,
-                                std::string* error) {
+                                NativeLibraryLoadError* error) {
   // dlopen() opens the file off disk.
   base::ThreadRestrictions::AssertIOAllowed();
 
@@ -25,7 +27,7 @@ NativeLibrary LoadNativeLibrary(const FilePath& library_path,
   // and http://crbug.com/40794.
   void* dl = dlopen(library_path.value().c_str(), RTLD_LAZY);
   if (!dl && error)
-    *error = dlerror();
+    error->message = dlerror();
 
   return dl;
 }
@@ -50,4 +52,10 @@ string16 GetNativeLibraryName(const string16& name) {
   return ASCIIToUTF16("lib") + name + ASCIIToUTF16(".so");
 }
 
+// static
+std::ostream& operator<<(std::ostream& out,
+                         const NativeLibraryLoadError& error) {
+  return out << error.message;
+}
+
 }  // namespace base