Add NULL-checks to plugin delegate message handlers

chrome/plugin/webplugin_delegate_stub.cc

Index: chrome/plugin/webplugin_delegate_stub.cc
diff --git a/chrome/plugin/webplugin_delegate_stub.cc b/chrome/plugin/webplugin_delegate_stub.cc
index 8e74aa7df290a6a4e4cb82cf67ed748a6d12837e..17f02222b28887e3e0f17ab1d65f5d94244334ba 100644
--- a/chrome/plugin/webplugin_delegate_stub.cc
+++ b/chrome/plugin/webplugin_delegate_stub.cc
@@ -337,29 +337,35 @@ void WebPluginDelegateStub::OnSendJavaScriptStream(const GURL& url,
 }
 
 void WebPluginDelegateStub::OnSetContentAreaFocus(bool has_focus) {
-  delegate_->SetContentAreaHasFocus(has_focus);
+  if (delegate_)
+    delegate_->SetContentAreaHasFocus(has_focus);
 }
 
 #if defined(OS_MACOSX)
 void WebPluginDelegateStub::OnSetWindowFocus(bool has_focus) {
-  delegate_->SetWindowHasFocus(has_focus);
+  if (delegate_)
+    delegate_->SetWindowHasFocus(has_focus);
 }
 
 void WebPluginDelegateStub::OnContainerHidden() {
-  delegate_->SetContainerVisibility(false);
+  if (delegate_)
+    delegate_->SetContainerVisibility(false);
 }
 
 void WebPluginDelegateStub::OnContainerShown(gfx::Rect window_frame,
                                              gfx::Rect view_frame,
                                              bool has_focus) {
-  delegate_->WindowFrameChanged(window_frame, view_frame);
-  delegate_->SetContainerVisibility(true);
-  delegate_->SetWindowHasFocus(has_focus);
+  if (delegate_) {
+    delegate_->WindowFrameChanged(window_frame, view_frame);
+    delegate_->SetContainerVisibility(true);
+    delegate_->SetWindowHasFocus(has_focus);
+  }
 }
 
 void WebPluginDelegateStub::OnWindowFrameChanged(const gfx::Rect& window_frame,
                                                  const gfx::Rect& view_frame) {
-  delegate_->WindowFrameChanged(window_frame, view_frame);
+  if (delegate_)
+    delegate_->WindowFrameChanged(window_frame, view_frame);
 }
 #endif  // OS_MACOSX