Bug 1191100 - Remove XPIDL signature comments in .cpp files. r=ehsan

Comment-only so DONTBUILD.

docshell/base/nsDocShell.cpp

@@ -1988,7 +1988,6 @@ nsDocShell::GetChromeEventHandler(nsIDOMEventTarget** aChromeEventHandler)
   return NS_OK;
 }
 
-/* void setCurrentURI (in nsIURI uri); */
 NS_IMETHODIMP
 nsDocShell::SetCurrentURI(nsIURI* aURI)
 {
@@ -7118,7 +7117,6 @@ nsDocShell::Embed(nsIContentViewer* aContentViewer,
   return NS_OK;
 }
 
-/* void setIsPrinting (in boolean aIsPrinting); */
 NS_IMETHODIMP
 nsDocShell::SetIsPrinting(bool aIsPrinting)
 {
@@ -12808,7 +12806,6 @@ nsDocShell::IsFrame()
   return !!parent;
 }
 
-/* boolean IsBeingDestroyed (); */
 NS_IMETHODIMP
 nsDocShell::IsBeingDestroyed(bool* aDoomed)
 {