Bug 1187801 part 3 - Add iframe fullscreen flag and stop auto-rollback when this flag presents. r=smaug

--HG--
extra : source : f7801f9c5b8e65862ead640f7b07ad87a40c9345

dom/base/nsDocument.cpp

@@ -155,6 +155,7 @@
 #include "nsHtml5TreeOpExecutor.h"
 #include "mozilla/dom/HTMLLinkElement.h"
 #include "mozilla/dom/HTMLMediaElement.h"
+#include "mozilla/dom/HTMLIFrameElement.h"
 #include "mozilla/dom/HTMLImageElement.h"
 #include "mozilla/dom/MediaSource.h"
 
@@ -11239,6 +11240,16 @@ nsDocument::RestorePreviousFullScreenState()
     nsDocument* theDoc = static_cast<nsDocument*>(doc);
     MOZ_ASSERT(!theDoc->mFullScreenStack.IsEmpty(),
                "Ancestor of fullscreen document must also be in fullscreen");
+    if (doc != this) {
+      Element* top = theDoc->FullScreenStackTop();
+      if (top->IsHTMLElement(nsGkAtoms::iframe)) {
+        if (static_cast<HTMLIFrameElement*>(top)->FullscreenFlag()) {
+          // If this is an iframe, and it explicitly requested
+          // fullscreen, don't rollback it automatically.
+          break;
+        }
+      }
+    }
     exitDocs.AppendElement(theDoc);
     if (theDoc->mFullScreenStack.Length() > 1) {
       break;
@@ -11361,6 +11372,10 @@ ClearFullscreenStateOnElement(Element* aElement)
   aElement->DeleteProperty(nsGkAtoms::vr_state);
   // Remove styles from existing top element.
   EventStateManager::SetFullScreenState(aElement, false);
+  // Reset iframe fullscreen flag.
+  if (aElement->IsHTMLElement(nsGkAtoms::iframe)) {
+    static_cast<HTMLIFrameElement*>(aElement)->SetFullscreenFlag(false);
+  }
 }
 
 void
@@ -11853,6 +11868,10 @@ nsDocument::ApplyFullscreen(const FullscreenRequest& aRequest)
   // in this document.
   DebugOnly<bool> x = FullScreenStackPush(elem);
   NS_ASSERTION(x, "Full-screen state of requesting doc should always change!");
+  // Set the iframe fullscreen flag.
+  if (elem->IsHTMLElement(nsGkAtoms::iframe)) {
+    static_cast<HTMLIFrameElement*>(elem)->SetFullscreenFlag(true);
+  }
   changed.AppendElement(this);
 
   // Propagate up the document hierarchy, setting the full-screen element as

dom/html/HTMLIFrameElement.h

@@ -184,6 +184,13 @@ public:
   // nsGenericHTMLFrameElement::GetFrameLoader is fine
   // nsGenericHTMLFrameElement::GetAppManifestURL is fine
 
+  // The fullscreen flag is set to true only when requestFullscreen is
+  // explicitly called on this <iframe> element. In case this flag is
+  // set, the fullscreen state of this element will not be reverted
+  // automatically when its subdocument exits fullscreen.
+  bool FullscreenFlag() const { return mFullscreenFlag; }
+  void SetFullscreenFlag(bool aValue) { mFullscreenFlag = aValue; }
+
 protected:
   virtual ~HTMLIFrameElement();
 

dom/html/nsGenericHTMLFrameElement.h

@@ -113,6 +113,11 @@ protected:
   bool mBrowserFrameListenersRegistered;
   bool mFrameLoaderCreationDisallowed;
 
+  // This flag is only used by <iframe>. See HTMLIFrameElement::
+  // FullscreenFlag() for details. It is placed here so that we
+  // do not bloat any struct.
+  bool mFullscreenFlag = false;
+
 private:
   void GetManifestURLByType(nsIAtom *aAppType, nsAString& aOut);
 };