DevTools: Load document (html) content from disk cache in page agent enabling.

Source/core/loader/FrameLoader.cpp

Index: Source/core/loader/FrameLoader.cpp
diff --git a/Source/core/loader/FrameLoader.cpp b/Source/core/loader/FrameLoader.cpp
index 3289609ec2743a3e464e4aaaa443079e5c06cc5e..8743e1b748aafbe73df9a700cbd4ed921322f517 100644
--- a/Source/core/loader/FrameLoader.cpp
+++ b/Source/core/loader/FrameLoader.cpp
@@ -1059,6 +1059,14 @@ void FrameLoader::restoreScrollPositionAndViewState()
     }
 }
 
+bool FrameLoader::requestFromHistoryForInspector(ResourceRequestCachePolicy cachePolicy, ResourceRequest* request)
+{
+    if (!m_currentItem)
+        return false;
+    *request = requestFromHistoryItem(m_currentItem.get(), cachePolicy);
+    return true;
+}
+
 void FrameLoader::detachChildren()
 {
     typedef Vector<RefPtr<LocalFrame> > FrameVector;