Revert 273547 "Reset scoped_ptr to make plugin crash before ente..."

trunk/src/pdf/instance.cc

Index: trunk/src/pdf/instance.cc
===================================================================
--- trunk/src/pdf/instance.cc	(revision 274853)
+++ trunk/src/pdf/instance.cc	(working copy)
@@ -308,10 +308,6 @@
 
 Instance::~Instance() {
   RemovePerInstanceObject(kPPPPdfInterface, this);
-  // TODO(vitalybuka): remove after crbug.com/372095 fixed.
-  // Reset to NULL to make it crash in HandleDocumentLoad if called for
-  // deleted instance. scoped_ptr::~scoped_ptr does not reset pointer to NULL.
-  engine_.reset();
 }
 
 bool Instance::Init(uint32_t argc, const char* argn[], const char* argv[]) {