Don't access DisplayItemClient::VisualRect() for cached display items.

third_party/WebKit/Source/platform/graphics/paint/DisplayItem.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/graphics/paint/DisplayItem.h"
 
 namespace blink {
 
 struct SameSizeAsDisplayItem {
   virtual ~SameSizeAsDisplayItem() {}  // Allocate vtable pointer.
   void* pointer;
+  LayoutRect rect;
   int i;
 #ifndef NDEBUG
   WTF::String debug_string_;
 #endif
 };
 static_assert(sizeof(DisplayItem) == sizeof(SameSizeAsDisplayItem),
               "DisplayItem should stay small");
 
 #ifndef NDEBUG
 
@@ skipping 215 matching lines @@
     // This is the original debug string which is in json format.
     string_builder.Append(ClientDebugString());
     return;
   }
 
   string_builder.Append(String::Format("client: \"%p", &Client()));
   if (!ClientDebugString().IsEmpty()) {
     string_builder.Append(' ');
     string_builder.Append(ClientDebugString());
   }
+  string_builder.Append("\", visualRect: \"");
+  string_builder.Append(VisualRect().ToString());
   string_builder.Append("\", type: \"");
   string_builder.Append(TypeAsDebugString(GetType()));
   string_builder.Append('"');
   if (skipped_cache_)
     string_builder.Append(", skippedCache: true");
 }
 
 #endif
 
 }  // namespace blink