Fixed the behaviour of form submit to match the standard: no submit is taken place when the form is…

third_party/WebKit/Source/core/html/HTMLFormElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLFormElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLFormElement.cpp b/third_party/WebKit/Source/core/html/HTMLFormElement.cpp
index dd75c5daae1fbcb830b111b104382efebc578db8..3e145614b542b71d9beab41bc90788b2d360dd38 100644
--- a/third_party/WebKit/Source/core/html/HTMLFormElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLFormElement.cpp
@@ -347,9 +347,12 @@ void HTMLFormElement::submit(Event* event,
   if (!view || !frame || !frame->page())
     return;
 
-  // See crbug.com/586749.
+  // https://html.spec.whatwg.org/multipage/forms.html#form-submission-algorithm
+  // 2. If form document is not connected, has no associated browsing context,
+  // or its active sandboxing flag set has its sandboxed forms browsing
+  // context flag set, then abort these steps without doing anything.
   if (!isConnected())
-    UseCounter::count(document(), UseCounter::FormSubmissionNotInDocumentTree);
+    return;

[tkent, 2016/10/13 22:19:06]

Let's show a console warning in order to notice what's wrong to a web developer.

[lunalu1, 2016/10/14 15:08:45]

Done.

 
   if (m_isSubmitting)
     return;