diff --git a/dom/base/Element.cpp b/dom/base/Element.cpp
index 115088cf696..b903ace5d6a 100644
--- a/dom/base/Element.cpp
+++ b/dom/base/Element.cpp
@@ -1744,7 +1744,7 @@ Element::UnbindFromTree(bool aDeep, bool aNullParent)
       nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
                                       NS_LITERAL_CSTRING("DOM"), OwnerDoc(),
                                       nsContentUtils::eDOM_PROPERTIES,
-                                      "RemovedFullScreenElement");
+                                      "RemovedFullscreenElement");
       // Fully exit full-screen.
       nsIDocument::ExitFullscreenInDocTree(OwnerDoc());
     }
@@ -3241,7 +3241,7 @@ GetFullScreenError(nsIDocument* aDoc)
   }
 
   if (!nsContentUtils::IsRequestFullScreenAllowed()) {
-    return "FullScreenDeniedNotInputDriven";
+    return "FullscreenDeniedNotInputDriven";
   }
 
   return nullptr;
diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index dce7d7221cc..90758640f3a 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -11578,20 +11578,20 @@ GetFullscreenError(nsIDocument* aDoc, bool aCallerIsChrome)
   }
 
   if (!nsContentUtils::IsFullScreenApiEnabled()) {
-    return "FullScreenDeniedDisabled";
+    return "FullscreenDeniedDisabled";
   }
   if (!aDoc->IsVisible()) {
-    return "FullScreenDeniedHidden";
+    return "FullscreenDeniedHidden";
   }
   if (HasFullScreenSubDocument(aDoc)) {
-    return "FullScreenDeniedSubDocFullScreen";
+    return "FullscreenDeniedSubDocFullScreen";
   }
 
   // Ensure that all containing elements are <iframe> and have
   // allowfullscreen attribute set.
   nsCOMPtr<nsIDocShell> docShell(aDoc->GetDocShell());
   if (!docShell || !docShell->GetFullscreenAllowed()) {
-    return "FullScreenDeniedContainerNotAllowed";
+    return "FullscreenDeniedContainerNotAllowed";
   }
 
   return nullptr;
@@ -11607,15 +11607,15 @@ nsDocument::FullscreenElementReadyCheck(Element* aElement,
     return false;
   }
   if (!aElement->IsInDoc()) {
-    DispatchFullscreenError("FullScreenDeniedNotInDocument");
+    DispatchFullscreenError("FullscreenDeniedNotInDocument");
     return false;
   }
   if (aElement->OwnerDoc() != this) {
-    DispatchFullscreenError("FullScreenDeniedMovedDocument");
+    DispatchFullscreenError("FullscreenDeniedMovedDocument");
     return false;
   }
   if (!GetWindow()) {
-    DispatchFullscreenError("FullScreenDeniedLostWindow");
+    DispatchFullscreenError("FullscreenDeniedLostWindow");
     return false;
   }
   if (const char* msg = GetFullscreenError(this, aWasCallerChrome)) {
@@ -11626,11 +11626,11 @@ nsDocument::FullscreenElementReadyCheck(Element* aElement,
       !nsContentUtils::ContentIsDescendantOf(aElement, GetFullscreenElement())) {
     // If this document is full-screen, only grant full-screen requests from
     // a descendant of the current full-screen element.
-    DispatchFullscreenError("FullScreenDeniedNotDescendant");
+    DispatchFullscreenError("FullscreenDeniedNotDescendant");
     return false;
   }
   if (!nsContentUtils::IsChromeDoc(this) && !IsInActiveTab(this)) {
-    DispatchFullscreenError("FullScreenDeniedNotFocusedTab");
+    DispatchFullscreenError("FullscreenDeniedNotFocusedTab");
     return false;
   }
   // Deny requests when a windowed plugin is focused.
@@ -11644,7 +11644,7 @@ nsDocument::FullscreenElementReadyCheck(Element* aElement,
   if (focusedElement) {
     nsCOMPtr<nsIContent> content = do_QueryInterface(focusedElement);
     if (nsContentUtils::HasPluginWithUncontrolledEventDispatch(content)) {
-      DispatchFullscreenError("FullScreenDeniedFocusedPlugin");
+      DispatchFullscreenError("FullscreenDeniedFocusedPlugin");
       return false;
     }
   }
diff --git a/dom/base/nsFocusManager.cpp b/dom/base/nsFocusManager.cpp
index 6c168f31c93..a3f00dfb221 100644
--- a/dom/base/nsFocusManager.cpp
+++ b/dom/base/nsFocusManager.cpp
@@ -1236,7 +1236,7 @@ nsFocusManager::SetFocusInner(nsIContent* aNewContent, int32_t aFlags,
                                     NS_LITERAL_CSTRING("DOM"),
                                     contentToFocus->OwnerDoc(),
                                     nsContentUtils::eDOM_PROPERTIES,
-                                    "FocusedWindowedPluginWhileFullScreen");
+                                    "FocusedWindowedPluginWhileFullscreen");
     nsIDocument::AsyncExitFullscreen(contentToFocus->OwnerDoc());
   }
 #endif
diff --git a/dom/locales/en-US/chrome/dom/dom.properties b/dom/locales/en-US/chrome/dom/dom.properties
index b423ed56a7e..a63f674dfee 100644
--- a/dom/locales/en-US/chrome/dom/dom.properties
+++ b/dom/locales/en-US/chrome/dom/dom.properties
@@ -64,19 +64,19 @@ EnablePrivilegeWarning=Use of enablePrivilege is deprecated.  Please use code th
 nsIJSONDecodeDeprecatedWarning=nsIJSON.decode is deprecated.  Please use JSON.parse instead.
 nsIJSONEncodeDeprecatedWarning=nsIJSON.encode is deprecated.  Please use JSON.stringify instead.
 nsIDOMWindowInternalWarning=Use of nsIDOMWindowInternal is deprecated. Use nsIDOMWindow instead.
-FullScreenDeniedDisabled=Request for full-screen was denied because full-screen API is disabled by user preference.
-FullScreenDeniedFocusedPlugin=Request for full-screen was denied because a windowed plugin is focused.
-FullScreenDeniedHidden=Request for full-screen was denied because the document is no longer visible.
-FullScreenDeniedContainerNotAllowed=Request for full-screen was denied because at least one of the document's containing elements is not an iframe or does not have an "allowfullscreen" attribute.
-FullScreenDeniedNotInputDriven=Request for full-screen was denied because Element.mozRequestFullScreen() was not called from inside a short running user-generated event handler.
-FullScreenDeniedNotInDocument=Request for full-screen was denied because requesting element is no longer in its document.
-FullScreenDeniedMovedDocument=Request for full-screen was denied because requesting element has moved document.
-FullScreenDeniedLostWindow=Request for full-screen was denied because we no longer have a window.
-FullScreenDeniedSubDocFullScreen=Request for full-screen was denied because a subdocument of the document requesting full-screen is already full-screen.
-FullScreenDeniedNotDescendant=Request for full-screen was denied because requesting element is not a descendant of the current full-screen element.
-FullScreenDeniedNotFocusedTab=Request for full-screen was denied because requesting element is not in the currently focused tab.
-RemovedFullScreenElement=Exited full-screen because full-screen element was removed from document.
-FocusedWindowedPluginWhileFullScreen=Exited full-screen because windowed plugin was focused.
+FullscreenDeniedDisabled=Request for fullscreen was denied because Fullscreen API is disabled by user preference.
+FullscreenDeniedFocusedPlugin=Request for fullscreen was denied because a windowed plugin is focused.
+FullscreenDeniedHidden=Request for fullscreen was denied because the document is no longer visible.
+FullscreenDeniedContainerNotAllowed=Request for fullscreen was denied because at least one of the document's containing elements is not an iframe or does not have an "allowfullscreen" attribute.
+FullscreenDeniedNotInputDriven=Request for fullscreen was denied because Element.requestFullscreen() was not called from inside a short running user-generated event handler.
+FullscreenDeniedNotInDocument=Request for fullscreen was denied because requesting element is no longer in its document.
+FullscreenDeniedMovedDocument=Request for fullscreen was denied because requesting element has moved document.
+FullscreenDeniedLostWindow=Request for fullscreen was denied because we no longer have a window.
+FullscreenDeniedSubDocFullscreen=Request for fullscreen was denied because a subdocument of the document requesting fullscreen is already fullscreen.
+FullscreenDeniedNotDescendant=Request for fullscreen was denied because requesting element is not a descendant of the current fullscreen element.
+FullscreenDeniedNotFocusedTab=Request for fullscreen was denied because requesting element is not in the currently focused tab.
+RemovedFullscreenElement=Exited fullscreen because fullscreen element was removed from document.
+FocusedWindowedPluginWhileFullscreen=Exited fullscreen because windowed plugin was focused.
 HTMLSyncXHRWarning=HTML parsing in XMLHttpRequest is not supported in the synchronous mode.
 InvalidRedirectChannelWarning=Unable to redirect to %S because the channel doesn't implement nsIWritablePropertyBag2.
 ResponseTypeSyncXHRWarning=Use of XMLHttpRequest's responseType attribute is no longer supported in the synchronous mode in window context.
diff --git a/webapprt/locales/en-US/webapprt/overrides/dom.properties b/webapprt/locales/en-US/webapprt/overrides/dom.properties
index 8f433724f02..b8342006da8 100644
--- a/webapprt/locales/en-US/webapprt/overrides/dom.properties
+++ b/webapprt/locales/en-US/webapprt/overrides/dom.properties
@@ -64,19 +64,19 @@ EnablePrivilegeWarning=Use of enablePrivilege is deprecated. Please use code tha
 nsIJSONDecodeDeprecatedWarning=nsIJSON.decode is deprecated. Please use JSON.parse instead.
 nsIJSONEncodeDeprecatedWarning=nsIJSON.encode is deprecated. Please use JSON.stringify instead.
 nsIDOMWindowInternalWarning=Use of nsIDOMWindowInternal is deprecated. Use nsIDOMWindow instead.
-FullScreenDeniedDisabled=Request for full-screen was denied because full-screen API is disabled by user preference.
-FullScreenDeniedFocusedPlugin=Request for full-screen was denied because a windowed plugin is focused.
-FullScreenDeniedHidden=Request for full-screen was denied because the document is no longer visible.
-FullScreenDeniedContainerNotAllowed=Request for full-screen was denied because at least one of the document's containing elements is not an iframe or does not have an "allowfullscreen" attribute.
-FullScreenDeniedNotInputDriven=Request for full-screen was denied because Element.mozRequestFullScreen() was not called from inside a short running user-generated event handler.
-FullScreenDeniedNotInDocument=Request for full-screen was denied because requesting element is no longer in its document.
-FullScreenDeniedMovedDocument=Request for full-screen was denied because requesting element has moved document.
-FullScreenDeniedLostWindow=Request for full-screen was denied because we no longer have a window.
-FullScreenDeniedSubDocFullScreen=Request for full-screen was denied because a subdocument of the document requesting full-screen is already full-screen.
-FullScreenDeniedNotDescendant=Request for full-screen was denied because requesting element is not a descendant of the current full-screen element.
-FullScreenDeniedNotFocusedTab=Request for full-screen was denied because requesting element is not in the currently focused tab.
-RemovedFullScreenElement=Exited full-screen because full-screen element was removed from document.
-FocusedWindowedPluginWhileFullScreen=Exited full-screen because windowed plugin was focused.
+FullscreenDeniedDisabled=Request for fullscreen was denied because Fullscreen API is disabled by user preference.
+FullscreenDeniedFocusedPlugin=Request for fullscreen was denied because a windowed plugin is focused.
+FullscreenDeniedHidden=Request for fullscreen was denied because the document is no longer visible.
+FullscreenDeniedContainerNotAllowed=Request for fullscreen was denied because at least one of the document's containing elements is not an iframe or does not have an "allowfullscreen" attribute.
+FullscreenDeniedNotInputDriven=Request for fullscreen was denied because Element.requestFullscreen() was not called from inside a short running user-generated event handler.
+FullscreenDeniedNotInDocument=Request for fullscreen was denied because requesting element is no longer in its document.
+FullscreenDeniedMovedDocument=Request for fullscreen was denied because requesting element has moved document.
+FullscreenDeniedLostWindow=Request for fullscreen was denied because we no longer have a window.
+FullscreenDeniedSubDocFullscreen=Request for fullscreen was denied because a subdocument of the document requesting fullscreen is already fullscreen.
+FullscreenDeniedNotDescendant=Request for fullscreen was denied because requesting element is not a descendant of the current fullscreen element.
+FullscreenDeniedNotFocusedTab=Request for fullscreen was denied because requesting element is not in the currently focused tab.
+RemovedFullscreenElement=Exited fullscreen because fullscreen element was removed from document.
+FocusedWindowedPluginWhileFullscreen=Exited fullscreen because windowed plugin was focused.
 HTMLSyncXHRWarning=HTML parsing in XMLHttpRequest is not supported in the synchronous mode.
 InvalidRedirectChannelWarning=Unable to redirect to %S because the channel doesn't implement nsIWritablePropertyBag2.
 ResponseTypeSyncXHRWarning=Use of XMLHttpRequest's responseType attribute is no longer supported in the synchronous mode in window context.