Don't bother layout until first navigation is done.

third_party/WebKit/Source/web/WebFrameContentDumper.cpp

Index: third_party/WebKit/Source/web/WebFrameContentDumper.cpp
diff --git a/third_party/WebKit/Source/web/WebFrameContentDumper.cpp b/third_party/WebKit/Source/web/WebFrameContentDumper.cpp
index c28d1fc6b208da451b2aa6c1d5fdfee9094e1314..a810a2ac000c68a77c17de8898a3a15f49815f75 100644
--- a/third_party/WebKit/Source/web/WebFrameContentDumper.cpp
+++ b/third_party/WebKit/Source/web/WebFrameContentDumper.cpp
@@ -28,7 +28,7 @@ static void frameContentAsPlainText(size_t maxChars, LocalFrame* frame, StringBu
         return;
 
     // Select the document body.
-    if (document->body()) {
+    if (!document->needsLayoutTreeUpdate() && document->body()) {
         const EphemeralRange range = EphemeralRange::rangeOfContents(*document->body());
 
         // The text iterator will walk nodes giving us text. This is similar to
@@ -52,6 +52,7 @@ static void frameContentAsPlainText(size_t maxChars, LocalFrame* frame, StringBu
         if (!curChild->isLocalFrame())
             continue;
         LocalFrame* curLocalChild = toLocalFrame(curChild);
+
         // Ignore the text of non-visible frames.
         LayoutView* contentLayoutObject = curLocalChild->contentLayoutObject();
         LayoutPart* ownerLayoutObject = curLocalChild->ownerLayoutObject();