Bug 717611 - Add nsConsoleService::ResetWindow to clear messages for a given window id; r=baku.

This will allow devtools to clear cached error messages, like
we already can with ConsoleAPI messages.

Differential Revision: https://phabricator.services.mozilla.com/D21693

--HG--
extra : moz-landing-system : lando

xpcom/base/nsConsoleService.cpp

@@ -452,6 +452,14 @@ nsConsoleService::Reset() {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsConsoleService::ResetWindow(uint64_t windowInnerId) {
+  MOZ_RELEASE_ASSERT(NS_IsMainThread());
+
+  ClearMessagesForWindowID(windowInnerId);
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsConsoleService::Observe(nsISupports* aSubject, const char* aTopic,
                           const char16_t* aData) {

xpcom/base/nsIConsoleService.idl

@@ -44,6 +44,11 @@ interface nsIConsoleService : nsISupports
      * Clear the message buffer (e.g. for privacy reasons).
      */
     void reset();
+
+    /**
+     * Clear the message buffer for a given window.
+     */
+    void resetWindow(in uint64_t windowInnerId);
 };