Make PepperTryCatch hold a reference on PepperPluginInstanceImpl

content/renderer/pepper/pepper_try_catch.h

Index: content/renderer/pepper/pepper_try_catch.h
diff --git a/content/renderer/pepper/pepper_try_catch.h b/content/renderer/pepper/pepper_try_catch.h
index dba90aa780a8be427c47900f42ab5af304a4e9a3..f562023ef2b06172a813865accc032ed3df56431 100644
--- a/content/renderer/pepper/pepper_try_catch.h
+++ b/content/renderer/pepper/pepper_try_catch.h
@@ -34,7 +34,14 @@ class CONTENT_EXPORT PepperTryCatch {
   ppapi::ScopedPPVar FromV8(v8::Handle<v8::Value> v8_value);
 
  protected:
-  PepperPluginInstanceImpl* instance_;
+  // Make sure that |instance_| is alive for the lifetime of PepperTryCatch.
+  // PepperTryCatch is used mostly in Pepper scripting code, where it can be
+  // possible to enter JavaScript synchronously which can cause the plugin to
+  // be deleted.
+  //
+  // Note that PepperTryCatch objects should only ever be on the stack, so this
+  // shouldn't keep the instance around for too long.

[bbudge, 2014/09/22 19:38:50]

Maybe a note on the constructor?

+  scoped_refptr<PepperPluginInstanceImpl> instance_;
 
   // Whether To/FromV8 should convert object vars. If set to
   // kDisallowObjectVars, an exception should be set if they are encountered