Revert of Sync requestFullscreen() and exitFullscreen() algorithms with the spec

third_party/WebKit/Source/web/WebRemoteFrameImpl.cpp

Index: third_party/WebKit/Source/web/WebRemoteFrameImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebRemoteFrameImpl.cpp b/third_party/WebKit/Source/web/WebRemoteFrameImpl.cpp
index ec573b5074669e8af726a4c74d915dc1d82b1178..29479f8ce9309bc445336da85dc05408c9601826 100644
--- a/third_party/WebKit/Source/web/WebRemoteFrameImpl.cpp
+++ b/third_party/WebKit/Source/web/WebRemoteFrameImpl.cpp
@@ -506,21 +506,24 @@ void WebRemoteFrameImpl::willEnterFullscreen() {
   HTMLFrameOwnerElement* ownerElement =
       toHTMLFrameOwnerElement(frame()->owner());
 
-  // Call |requestFullscreen()| on |ownerElement| to make it the pending
-  // fullscreen element in anticipation of the coming |didEnterFullscreen()|
-  // call.
+  // Call requestFullscreen() on |ownerElement| to make it the provisional
+  // fullscreen element in FullscreenController, and to prepare
+  // fullscreenchange events that will need to fire on it and its (local)
+  // ancestors. The events will be triggered if/when fullscreen is entered.
   //
-  // PrefixedForCrossProcessDescendant is necessary because:
-  //  - The fullscreen element ready check and other checks should be bypassed.
-  //  - |ownerElement| will need :-webkit-full-screen-ancestor style in addition
-  //    to :-webkit-full-screen.
+  // Passing |forCrossProcessAncestor| to requestFullscreen is necessary
+  // because:
+  // - |ownerElement| will need :-webkit-full-screen-ancestor style in
+  //   addition to :-webkit-full-screen.
+  // - there's no need to resend the ToggleFullscreen IPC to the browser
+  //   process.
   //
   // TODO(alexmos): currently, this assumes prefixed requests, but in the
   // future, this should plumb in information about which request type
   // (prefixed or unprefixed) to use for firing fullscreen events.
-  Fullscreen::requestFullscreen(
-      *ownerElement,
-      Fullscreen::RequestType::PrefixedForCrossProcessDescendant);
+  Fullscreen::requestFullscreen(*ownerElement,
+                                Fullscreen::RequestType::Prefixed,
+                                true /* forCrossProcessAncestor */);
 }
 
 void WebRemoteFrameImpl::setHasReceivedUserGesture() {