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 a79947cc4f5f5057d79e216c8cd246e3c11c5bf5..97d4925eca6c3a85d5febee50a304f6d04b1e852 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -5314,8 +5314,8 @@ void Document::exitPointerLock()
     if (Element* target = page()->pointerLockController().element()) {
         if (target->document() != this)
             return;
+        page()->pointerLockController().requestPointerUnlock();
     }
-    page()->pointerLockController().requestPointerUnlock();
 }
 
 Element* Document::pointerLockElement() const