Moved addStylesheetByUrl to it's own section.

This was a suggestion by dcheng in https://codereview.chromium.org/309143002/. Added a // Navigation transitions ----- section and moved the function there.

BUG=

Review URL: https://codereview.chromium.org/324153003

git-svn-id: svn://svn.chromium.org/blink/trunk@175933 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/public/web/WebFrame.h

@@ -470,10 +470,12 @@ public:
     virtual bool setCompositionFromExistingText(int compositionStart, int compositionEnd, const WebVector<WebCompositionUnderline>& underlines) = 0;
     virtual void extendSelectionAndDelete(int before, int after) = 0;
 
-    virtual void addStyleSheetByURL(const WebString& url) = 0;
-
     virtual void setCaretVisible(bool) = 0;
 
+    // Navigation Transitions  ---------------------------------------------
+
+    virtual void addStyleSheetByURL(const WebString& url) = 0;
+
     // Printing ------------------------------------------------------------
 
     // Reformats the WebFrame for printing. WebPrintParams specifies the printable