Implement pointer lock API for out-of-process iframes.

third_party/WebKit/Source/core/dom/Document.cpp

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index 587c08a0dbf5b3bc767b255262741682be3266e7..086fb9f2af9520c4e1673a2b0330e4ad02c70c4e 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -5335,8 +5335,8 @@ void Document::exitPointerLock()
     if (Element* target = page()->pointerLockController().element()) {
         if (target->document() != this)
             return;
+        page()->pointerLockController().requestPointerUnlock();
     }
-    page()->pointerLockController().requestPointerUnlock();
 }
 
 Element* Document::pointerLockElement() const