Bug 1446499: Use static nsWindowsDllInterceptor in plugin's HookProtectedMode r=aklotz

HookProtectedMode requires its nsWindowsDllInterceptor to last as long as the functions need to be overridden.  This uses a static object instead of a local one.

--HG--
extra : rebase_source : 7ba3f2fc1e19f89936b7f7fa490554e9cf9b885c

dom/plugins/ipc/FunctionHook.cpp

@@ -296,14 +296,21 @@ CreateFileWHookFn(LPCWSTR aFname, DWORD aAccess, DWORD aShare,
 
 void FunctionHook::HookProtectedMode()
 {
+  // Make sure we only do this once.
+  static bool sRunOnce = false;
+  if (sRunOnce) {
+    return;
+  }
+  sRunOnce = true;
+
   // Legacy code.  Uses the nsWindowsDLLInterceptor directly instead of
   // using the FunctionHook
+  sKernel32Intercept.Init("kernel32.dll");
   MOZ_ASSERT(XRE_GetProcessType() == GeckoProcessType_Plugin);
-  WindowsDllInterceptor k32Intercept("kernel32.dll");
-  k32Intercept.AddHook("CreateFileW",
+  sKernel32Intercept.AddHook("CreateFileW",
                              reinterpret_cast<intptr_t>(CreateFileWHookFn),
                              (void**) &sCreateFileWStub);
-  k32Intercept.AddHook("CreateFileA",
+  sKernel32Intercept.AddHook("CreateFileA",
                              reinterpret_cast<intptr_t>(CreateFileAHookFn),
                              (void**) &sCreateFileAStub);
 }