--- a/b2g/components/FilePicker.js
+++ b/b2g/components/FilePicker.js
@@ -66,21 +66,22 @@ FilePicker.prototype = {
       throw Cr.NS_ERROR_NOT_IMPLEMENTED;
     }
   },
 
   /* readonly attribute nsILocalFile file - not implemented; */
   /* readonly attribute nsISimpleEnumerator files - not implemented; */
   /* readonly attribute nsIURI fileURL - not implemented; */
 
-  get domfiles() {
+  get domFileOrDirectoryEnumerator() {
     return this.mFilesEnumerator;
   },
 
-  get domfile() {
+  // We don't support directory selection yet.
+  get domFileOrDirectory() {
     return this.mFilesEnumerator ? this.mFilesEnumerator.mFiles[0] : null;
   },
 
   get mode() {
     return this.mMode;
   },
 
   appendFilters: function(filterMask) {

--- a/dom/html/HTMLInputElement.cpp
+++ b/dom/html/HTMLInputElement.cpp
@@ -381,17 +381,18 @@ HTMLInputElement::nsFilePickerShownCallb
 
   int16_t mode;
   mFilePicker->GetMode(&mode);
 
   // Collect new selected filenames
   nsTArray<RefPtr<File>> newFiles;
   if (mode == static_cast<int16_t>(nsIFilePicker::modeOpenMultiple)) {
     nsCOMPtr<nsISimpleEnumerator> iter;
-    nsresult rv = mFilePicker->GetDomfiles(getter_AddRefs(iter));
+    nsresult rv =
+      mFilePicker->GetDomFileOrDirectoryEnumerator(getter_AddRefs(iter));
     NS_ENSURE_SUCCESS(rv, rv);
 
     if (!iter) {
       return NS_OK;
     }
 
     nsCOMPtr<nsISupports> tmp;
     bool hasMore = true;
@@ -404,17 +405,17 @@ HTMLInputElement::nsFilePickerShownCallb
       if (domBlob) {
         newFiles.AppendElement(static_cast<File*>(domBlob.get()));
       }
     }
   } else {
     MOZ_ASSERT(mode == static_cast<int16_t>(nsIFilePicker::modeOpen) ||
                mode == static_cast<int16_t>(nsIFilePicker::modeGetFolder));
     nsCOMPtr<nsISupports> tmp;
-    nsresult rv = mFilePicker->GetDomfile(getter_AddRefs(tmp));
+    nsresult rv = mFilePicker->GetDomFileOrDirectory(getter_AddRefs(tmp));
     NS_ENSURE_SUCCESS(rv, rv);
 
     nsCOMPtr<nsIDOMBlob> blob = do_QueryInterface(tmp);
     if (blob) {
       RefPtr<File> file = static_cast<Blob*>(blob.get())->ToFile();
       newFiles.AppendElement(file);
     }
   }

--- a/mobile/android/components/FilePicker.js
+++ b/mobile/android/components/FilePicker.js
@@ -135,32 +135,33 @@ FilePicker.prototype = {
   },
 
   get files() {
     return this.getEnumerator([this.file], function(file) {
       return file;
     });
   },
 
-  get domfile() {
+  // We don't support directory selection yet.
+  get domFileOrDirectory() {
     let f = this.file;
     if (!f) {
         return null;
     }
 
     let win = this._domWin;
     if (win) {
       let utils = win.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
       return utils.wrapDOMFile(f);
     }
 
     return new File(f);
   },
 
-  get domfiles() {
+  get domFileOrDirectoryEnumerator() {
     let win = this._domWin;
     return this.getEnumerator([this.file], function(file) {
       if (win) {
         let utils = win.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
         return utils.wrapDOMFile(file);
       }
 
       return new File(file);

--- a/mobile/android/tests/browser/robocop/testFilePicker.js
+++ b/mobile/android/tests/browser/robocop/testFilePicker.js
@@ -26,24 +26,25 @@ add_test(function filepicker_open() {
 
       let files = fp.files;
       while (files.hasMoreElements()) {
         let file = files.getNext().QueryInterface(Ci.nsIFile);
         do_print("File: " + file.path);
         is(file.path, "/mnt/sdcard/my-favorite-martian.png", "Retrieve the right martian file from array!");
       }
 
-      do_print("DOMFile: " + fp.domfile.mozFullPath);
-      is(fp.domfile.mozFullPath, "/mnt/sdcard/my-favorite-martian.png", "Retrieve the right martian domfile!");
+      let file = fp.domFileOrDirectory;
+      do_print("DOMFile: " + file.mozFullPath);
+      is(file.mozFullPath, "/mnt/sdcard/my-favorite-martian.png", "Retrieve the right martian DOM File!");
 
-      let domfiles = fp.domfiles;
-      while (domfiles.hasMoreElements()) {
-        let domfile = domfiles.getNext();
-        do_print("DOMFile: " + domfile.mozFullPath);
-        is(domfile.mozFullPath, "/mnt/sdcard/my-favorite-martian.png", "Retrieve the right martian file from domfile array!");
+      let e = fp.domFileOrDirectoryEnumerator;
+      while (e.hasMoreElements()) {
+        let file = e.getNext();
+        do_print("DOMFile: " + file.mozFullPath);
+        is(file.mozFullPath, "/mnt/sdcard/my-favorite-martian.png", "Retrieve the right martian file from domFileOrDirectoryEnumerator array!");
       }
 
       do_test_finished();
 
       run_next_test();
     }
   };
 

--- a/testing/specialpowers/content/MockFilePicker.jsm
+++ b/testing/specialpowers/content/MockFilePicker.jsm
@@ -141,17 +141,19 @@ MockFilePickerInstance.prototype = {
     if (MockFilePicker.returnFiles.length >= 1 &&
         // window.File does not implement nsIFile
         MockFilePicker.isNsIFile(MockFilePicker.returnFiles[0])) {
       return MockFilePicker.returnFiles[0];
     }
 
     return null;
   },
-  get domfile()  {
+
+  // We don't support directories here.
+  get domFileOrDirectory()  {
     if (MockFilePicker.returnFiles.length >= 1) {
       // window.File does not implement nsIFile
       if (!MockFilePicker.isNsIFile(MockFilePicker.returnFiles[0])) {
         return MockFilePicker.returnFiles[0];
       }
 
       let utils = this.parent.QueryInterface(Ci.nsIInterfaceRequestor)
                              .getInterface(Ci.nsIDOMWindowUtils);
@@ -179,17 +181,17 @@ MockFilePickerInstance.prototype = {
         // window.File does not implement nsIFile
         if (!MockFilePicker.isNsIFile(MockFilePicker.returnFiles[this.index])) {
           return null;
         }
         return MockFilePicker.returnFiles[this.index++];
       }
     };
   },
-  get domfiles()  {
+  get domFileOrDirectoryEnumerator()  {
     let utils = this.parent.QueryInterface(Ci.nsIInterfaceRequestor)
                            .getInterface(Ci.nsIDOMWindowUtils);
     return {
       index: 0,
       QueryInterface: XPCOMUtils.generateQI([Ci.nsISimpleEnumerator]),
       hasMoreElements: function() {
         return this.index < MockFilePicker.returnFiles.length;
       },

--- a/toolkit/components/filepicker/nsFilePicker.js
+++ b/toolkit/components/filepicker/nsFilePicker.js
@@ -88,24 +88,24 @@ nsFilePicker.prototype = {
   },
 
   /* readonly attribute nsILocalFile file; */
   get file()  { return this.mFilesEnumerator.mFiles[0]; },
 
   /* readonly attribute nsISimpleEnumerator files; */
   get files()  { return this.mFilesEnumerator; },
 
-  /* readonly attribute DOM File domfile; */
-  get domfile()  {
-    let enumerator = this.domfiles;
+  /* we don't support directories, yet */
+  get domFileOrDirectory()  {
+    let enumerator = this.domFileOrDirectoryEnumerator;
     return enumerator ? enumerator.mFiles[0] : null;
   },
 
-  /* readonly attribute nsISimpleEnumerator domfiles; */
-  get domfiles()  {
+  /* readonly attribute nsISimpleEnumerator domFileOrDirectoryEnumerator; */
+  get domFileOrDirectoryEnumerator()  {
     if (!this.mFilesEnumerator) {
       return null;
     }
 
     if (!this.mDOMFilesEnumerator) {
       this.mDOMFilesEnumerator = {
         QueryInterface: XPCOMUtils.generateQI([Components.interfaces.nsISimpleEnumerator]),
 

--- a/widget/nsBaseFilePicker.cpp
+++ b/widget/nsBaseFilePicker.cpp
@@ -332,39 +332,39 @@ nsBaseFilePicker::SetAddToRecentDocs(boo
 NS_IMETHODIMP
 nsBaseFilePicker::GetMode(int16_t* aMode)
 {
   *aMode = mMode;
   return NS_OK;
 }
 
 NS_IMETHODIMP
-nsBaseFilePicker::GetDomfile(nsISupports** aDomfile)
+nsBaseFilePicker::GetDomFileOrDirectory(nsISupports** aValue)
 {
   nsCOMPtr<nsIFile> localFile;
   nsresult rv = GetFile(getter_AddRefs(localFile));
   NS_ENSURE_SUCCESS(rv, rv);
 
   if (!localFile) {
-    *aDomfile = nullptr;
+    *aValue = nullptr;
     return NS_OK;
   }
 
   RefPtr<File> domFile = File::CreateFromFile(mParent, localFile);
   domFile->Impl()->SetIsDirectory(mMode == nsIFilePicker::modeGetFolder);
-  nsCOMPtr<nsIDOMBlob>(domFile).forget(aDomfile);
+  nsCOMPtr<nsIDOMBlob>(domFile).forget(aValue);
   return NS_OK;
 }
 
 NS_IMETHODIMP
-nsBaseFilePicker::GetDomfiles(nsISimpleEnumerator** aDomfiles)
+nsBaseFilePicker::GetDomFileOrDirectoryEnumerator(nsISimpleEnumerator** aValue)
 {
   nsCOMPtr<nsISimpleEnumerator> iter;
   nsresult rv = GetFiles(getter_AddRefs(iter));
   NS_ENSURE_SUCCESS(rv, rv);
 
   RefPtr<nsBaseFilePickerEnumerator> retIter =
     new nsBaseFilePickerEnumerator(mParent, iter, mMode);
 
-  retIter.forget(aDomfiles);
+  retIter.forget(aValue);
   return NS_OK;
 }
 

--- a/widget/nsBaseFilePicker.h
+++ b/widget/nsBaseFilePicker.h
@@ -32,18 +32,18 @@ public:
   NS_IMETHOD SetFilterIndex(int32_t aFilterIndex);
   NS_IMETHOD GetFiles(nsISimpleEnumerator **aFiles);
   NS_IMETHOD GetDisplayDirectory(nsIFile * *aDisplayDirectory);
   NS_IMETHOD SetDisplayDirectory(nsIFile * aDisplayDirectory);
   NS_IMETHOD GetAddToRecentDocs(bool *aFlag);
   NS_IMETHOD SetAddToRecentDocs(bool aFlag);
   NS_IMETHOD GetMode(int16_t *aMode);
 
-  NS_IMETHOD GetDomfile(nsISupports** aDomfile);
-  NS_IMETHOD GetDomfiles(nsISimpleEnumerator** aDomfiles);
+  NS_IMETHOD GetDomFileOrDirectory(nsISupports** aValue);
+  NS_IMETHOD GetDomFileOrDirectoryEnumerator(nsISimpleEnumerator** aValue);
 
 protected:
 
   virtual void InitNative(nsIWidget *aParent, const nsAString& aTitle) = 0;
 
   bool mAddToRecentDocs;
   nsCOMPtr<nsIFile> mDisplayDirectory;
 

--- a/widget/nsFilePickerProxy.cpp
+++ b/widget/nsFilePickerProxy.cpp
@@ -98,31 +98,31 @@ nsFilePickerProxy::SetFilterIndex(int32_
 {
   mSelectedType = aFilterIndex;
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsFilePickerProxy::GetFile(nsIFile** aFile)
 {
-  MOZ_ASSERT(false, "GetFile is unimplemented; use GetDomfile");
+  MOZ_ASSERT(false, "GetFile is unimplemented; use GetDomFileOrDirectory");
   return NS_ERROR_FAILURE;
 }
 
 NS_IMETHODIMP
 nsFilePickerProxy::GetFileURL(nsIURI** aFileURL)
 {
-  MOZ_ASSERT(false, "GetFileURL is unimplemented; use GetDomfile");
+  MOZ_ASSERT(false, "GetFileURL is unimplemented; use GetDomFileOrDirectory");
   return NS_ERROR_FAILURE;
 }
 
 NS_IMETHODIMP
 nsFilePickerProxy::GetFiles(nsISimpleEnumerator** aFiles)
 {
-  MOZ_ASSERT(false, "GetFiles is unimplemented; use GetDomfiles");
+  MOZ_ASSERT(false, "GetFiles is unimplemented; use GetDomFileOrDirectoryEnumerator");
   return NS_ERROR_FAILURE;
 }
 
 NS_IMETHODIMP
 nsFilePickerProxy::Show(int16_t* aReturn)
 {
   MOZ_ASSERT(false, "Show is unimplemented; use Open");
   return NS_ERROR_NOT_IMPLEMENTED;
@@ -157,39 +157,39 @@ nsFilePickerProxy::Recv__delete__(const 
 
       if (!blobImpl->IsFile()) {
         return true;
       }
 
       RefPtr<File> file = File::Create(mParent, blobImpl);
       MOZ_ASSERT(file);
 
-      mDomfiles.AppendElement(file);
+      mFilesOrDirectories.AppendElement(file);
     }
   }
 
   if (mCallback) {
     mCallback->Done(aResult);
     mCallback = nullptr;
   }
 
   return true;
 }
 
 NS_IMETHODIMP
-nsFilePickerProxy::GetDomfile(nsISupports** aDomfile)
+nsFilePickerProxy::GetDomFileOrDirectory(nsISupports** aValue)
 {
-  *aDomfile = nullptr;
-  if (mDomfiles.IsEmpty()) {
+  *aValue = nullptr;
+  if (mFilesOrDirectories.IsEmpty()) {
     return NS_OK;
   }
 
-  MOZ_ASSERT(mDomfiles.Length() == 1);
-  nsCOMPtr<nsIDOMBlob> blob = mDomfiles[0].get();
-  blob.forget(aDomfile);
+  MOZ_ASSERT(mFilesOrDirectories.Length() == 1);
+  nsCOMPtr<nsIDOMBlob> blob = mFilesOrDirectories[0].get();
+  blob.forget(aValue);
   return NS_OK;
 }
 
 namespace {
 
 class SimpleEnumerator final : public nsISimpleEnumerator
 {
 public:
@@ -226,14 +226,14 @@ private:
   uint32_t mIndex;
 };
 
 NS_IMPL_ISUPPORTS(SimpleEnumerator, nsISimpleEnumerator)
 
 } // namespace
 
 NS_IMETHODIMP
-nsFilePickerProxy::GetDomfiles(nsISimpleEnumerator** aDomfiles)
+nsFilePickerProxy::GetDomFileOrDirectoryEnumerator(nsISimpleEnumerator** aDomfiles)
 {
-  RefPtr<SimpleEnumerator> enumerator = new SimpleEnumerator(mDomfiles);
+  RefPtr<SimpleEnumerator> enumerator = new SimpleEnumerator(mFilesOrDirectories);
   enumerator.forget(aDomfiles);
   return NS_OK;
 }

--- a/widget/nsFilePickerProxy.h
+++ b/widget/nsFilePickerProxy.h
@@ -46,31 +46,31 @@ public:
     NS_IMETHODIMP GetDefaultExtension(nsAString& aDefaultExtension) override;
     NS_IMETHODIMP SetDefaultExtension(const nsAString& aDefaultExtension) override;
     NS_IMETHODIMP GetFilterIndex(int32_t* aFilterIndex) override;
     NS_IMETHODIMP SetFilterIndex(int32_t aFilterIndex) override;
     NS_IMETHODIMP GetFile(nsIFile** aFile) override;
     NS_IMETHODIMP GetFileURL(nsIURI** aFileURL) override;
     NS_IMETHODIMP GetFiles(nsISimpleEnumerator** aFiles) override;
 
-    NS_IMETHODIMP GetDomfile(nsISupports** aFile) override;
-    NS_IMETHODIMP GetDomfiles(nsISimpleEnumerator** aFiles) override;
+    NS_IMETHODIMP GetDomFileOrDirectory(nsISupports** aValue) override;
+    NS_IMETHODIMP GetDomFileOrDirectoryEnumerator(nsISimpleEnumerator** aValue) override;
 
     NS_IMETHODIMP Show(int16_t* aReturn) override;
     NS_IMETHODIMP Open(nsIFilePickerShownCallback* aCallback) override;
 
     // PFilePickerChild
     virtual bool
     Recv__delete__(const MaybeInputFiles& aFiles, const int16_t& aResult) override;
 
 private:
     ~nsFilePickerProxy();
     void InitNative(nsIWidget*, const nsAString&) override;
 
-    nsTArray<RefPtr<mozilla::dom::File>> mDomfiles;
+    nsTArray<RefPtr<mozilla::dom::File>> mFilesOrDirectories;
     nsCOMPtr<nsIFilePickerShownCallback> mCallback;
 
     int16_t   mSelectedType;
     nsString  mFile;
     nsString  mDefault;
     nsString  mDefaultExtension;
 
     InfallibleTArray<nsString> mFilters;

--- a/widget/nsIFilePicker.idl
+++ b/widget/nsIFilePicker.idl
@@ -18,17 +18,17 @@ interface nsIFilePickerShownCallback : n
   * Callback which is called when a filepicker is shown and a result
   * is returned.
   *
   * @param aResult One of returnOK, returnCancel, or returnReplace
   */
   void done(in short aResult);
 };
 
-[scriptable, uuid(9840d564-42c8-4d78-9a4d-71002343c918)]
+[scriptable, uuid(2a74ba0d-ffdd-4dad-b78a-98635e525a38)]
 interface nsIFilePicker : nsISupports
 {
   const short modeOpen        = 0;              // Load a file or directory
   const short modeSave        = 1;              // Save a file or directory
   const short modeGetFolder   = 2;              // Select a folder/directory
   const short modeOpenMultiple= 3;              // Load multiple files
 
   const short returnOK        = 0;              // User hit Ok, process selection
@@ -137,29 +137,29 @@ interface nsIFilePicker : nsISupports
   * Get the enumerator for the selected files
   * only works in the modeOpenMultiple mode
   *
   * @return Returns the files currently selected
   */
   readonly attribute nsISimpleEnumerator files;
 
  /**
-  * Get the DOM File for the file.
+  * Get the DOM File or the DOM Directory
   *
-  * @return Returns the file currently selected as File
+  * @return Returns the file or directory currently selected DOM object.
   */
-  readonly attribute nsISupports domfile;
+  readonly attribute nsISupports domFileOrDirectory;
 
  /**
-  * Get the enumerator for the selected files
+  * Get the enumerator for the selected files or directories
   * only works in the modeOpenMultiple mode
   *
-  * @return Returns the files currently selected as Files
+  * @return Returns the files/directories currently selected as DOM object.
   */
-  readonly attribute nsISimpleEnumerator domfiles;
+  readonly attribute nsISimpleEnumerator domFileOrDirectoryEnumerator;
 
  /**
   * Controls whether the chosen file(s) should be added to the system's recent
   * documents list. This attribute will be ignored if the system has no "Recent
   * Docs" concept, or if the application is in private browsing mode (in which
   * case the file will not be added). Defaults to true.
   */
   attribute boolean addToRecentDocs;