Bug 969671 - Warn about use of sync XHR in the main thread, r=sicking/ehsan

--HG--
extra : rebase_source : 4af00da28a4e8b6cc1209d9a5e098d9914286deb

content/base/public/nsDeprecatedOperationList.h

@@ -38,3 +38,4 @@ DEPRECATED_OPERATION(UseOfReleaseEvents)
 DEPRECATED_OPERATION(UseOfDOM3LoadMethod)
 DEPRECATED_OPERATION(ShowModalDialog)
 DEPRECATED_OPERATION(Window_Content)
+DEPRECATED_OPERATION(SyncXMLHttpRequest)

content/base/src/nsXMLHttpRequest.cpp

@@ -273,6 +273,9 @@ nsXMLHttpRequestUpload::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope)
 //
 /////////////////////////////////////////////
 
+bool
+nsXMLHttpRequest::sDontWarnAboutSyncXHR = false;
+
 nsXMLHttpRequest::nsXMLHttpRequest()
   : mResponseBodyDecodedPos(0),
     mResponseType(XML_HTTP_RESPONSE_TYPE_DEFAULT),
@@ -1541,6 +1544,11 @@ nsXMLHttpRequest::Open(const nsACString& method, const nsACString& url,
 {
   NS_ENSURE_ARG(!method.IsEmpty());
 
+  if (!async && !DontWarnAboutSyncXHR() && GetOwner() &&
+      GetOwner()->GetExtantDoc()) {
+    GetOwner()->GetExtantDoc()->WarnOnceAbout(nsIDocument::eSyncXMLHttpRequest);
+  }
+
   Telemetry::Accumulate(Telemetry::XMLHTTPREQUEST_ASYNC_OR_SYNC,
                         async ? 0 : 1);
 

content/base/src/nsXMLHttpRequest.h

@@ -533,6 +533,14 @@ public:
 
   virtual void DisconnectFromOwner() MOZ_OVERRIDE;
 
+  static void SetDontWarnAboutSyncXHR(bool aVal)
+  {
+    sDontWarnAboutSyncXHR = aVal;
+  }
+  static bool DontWarnAboutSyncXHR()
+  {
+    return sDontWarnAboutSyncXHR;
+  }
 protected:
   nsresult DetectCharset();
   nsresult AppendToResponseText(const char * aBuffer, uint32_t aBufferLen);
@@ -736,6 +744,25 @@ protected:
 
   // Helper object to manage our XPCOM scriptability bits
   nsXMLHttpRequestXPCOMifier* mXPCOMifier;
+
+  static bool sDontWarnAboutSyncXHR;
+};
+
+class MOZ_STACK_CLASS AutoDontWarnAboutSyncXHR
+{
+public:
+  AutoDontWarnAboutSyncXHR() : mOldVal(nsXMLHttpRequest::DontWarnAboutSyncXHR())
+  {
+    nsXMLHttpRequest::SetDontWarnAboutSyncXHR(true);
+  }
+
+  ~AutoDontWarnAboutSyncXHR()
+  {
+    nsXMLHttpRequest::SetDontWarnAboutSyncXHR(mOldVal);
+  }
+
+private:
+  bool mOldVal;
 };
 
 // A shim class designed to expose the non-DOM interfaces of

dom/locales/en-US/chrome/dom/dom.properties

@@ -144,4 +144,6 @@ UseOfDOM3LoadMethodWarning=Use of document.load() is deprecated. To upgrade your
 ShowModalDialogWarning=Use of window.showModalDialog() is deprecated. Use window.open() instead. For more help https://developer.mozilla.org/en-US/docs/Web/API/Window.open
 # LOCALIZATION NOTE: Do not translate "window._content" or "window.content"
 Window_ContentWarning=window._content is deprecated.  Please use window.content instead.
+# LOCALIZATION NOTE: Do not translate "XMLHttpRequest"
+SyncXMLHttpRequestWarning=Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help http://xhr.spec.whatwg.org/
 ImplicitMetaViewportTagFallback=No meta-viewport tag found. Please explicitly specify one to prevent unexpected behavioural changes in future versions. For more help https://developer.mozilla.org/en/docs/Mozilla/Mobile/Viewport_meta_tag

layout/base/nsDocumentViewer.cpp

@@ -115,6 +115,7 @@ static const char sPrintOptionsContractID[] =
 #include "nsISHistoryInternal.h"
 #include "nsIWebNavigation.h"
 #include "nsEventDispatcher.h"
+#include "nsXMLHttpRequest.h"
 
 //paint forcing
 #include <stdio.h>
@@ -1071,6 +1072,8 @@ nsDocumentViewer::PermitUnloadInternal(bool aCallerClosesWindow,
                                        bool *aShouldPrompt,
                                        bool *aPermitUnload)
 {
+  AutoDontWarnAboutSyncXHR disableSyncXHRWarning;
+
   *aPermitUnload = true;
 
   if (!mDocument
@@ -1276,6 +1279,8 @@ nsDocumentViewer::ResetCloseWindow()
 NS_IMETHODIMP
 nsDocumentViewer::PageHide(bool aIsUnload)
 {
+  AutoDontWarnAboutSyncXHR disableSyncXHRWarning;
+
   mHidden = true;
 
   if (!mDocument) {

webapprt/locales/en-US/webapprt/overrides/dom.properties

@@ -144,3 +144,5 @@ UseOfDOM3LoadMethodWarning=Use of document.load() is deprecated. To upgrade your
 ShowModalDialogWarning=Use of window.showModalDialog() is deprecated. Use window.open() instead. For more help https://developer.mozilla.org/en-US/docs/Web/API/Window.open
 # LOCALIZATION NOTE: Do not translate "window._content" or "window.content"
 Window_ContentWarning=window._content is deprecated. Please use window.content instead.
+# LOCALIZATION NOTE: Do not translate "XMLHttpRequest"
+SyncXMLHttpRequestWarning=Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help http://xhr.spec.whatwg.org/