Everywhere: Rename ASSERT => VERIFY

(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)

Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.

We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.

Userland/Libraries/LibWeb/DOM/Document.cpp

@@ -89,8 +89,8 @@ Document::~Document()
 
 void Document::removed_last_ref()
 {
-    ASSERT(!ref_count());
-    ASSERT(!m_deletion_has_begun);
+    VERIFY(!ref_count());
+    VERIFY(!m_deletion_has_begun);
 
     if (m_referencing_node_count) {
         // The document has reached ref_count==0 but still has nodes keeping it alive.
@@ -121,8 +121,8 @@ void Document::removed_last_ref()
             });
 
             for (auto& node : descendants) {
-                ASSERT(&node.document() == this);
-                ASSERT(!node.is_document());
+                VERIFY(&node.document() == this);
+                VERIFY(!node.is_document());
                 if (node.parent())
                     node.parent()->remove_child(node);
             }
@@ -299,7 +299,7 @@ void Document::attach_to_frame(Badge<Frame>, Frame& frame)
 
 void Document::detach_from_frame(Badge<Frame>, Frame& frame)
 {
-    ASSERT(&frame == m_frame);
+    VERIFY(&frame == m_frame);
     tear_down_layout_tree();
     m_frame = nullptr;
 }

Userland/Libraries/LibWeb/DOM/Document.h

@@ -259,14 +259,14 @@ private:
 
     void increment_referencing_node_count()
     {
-        ASSERT(!m_deletion_has_begun);
+        VERIFY(!m_deletion_has_begun);
         ++m_referencing_node_count;
     }
 
     void decrement_referencing_node_count()
     {
-        ASSERT(!m_deletion_has_begun);
-        ASSERT(m_referencing_node_count);
+        VERIFY(!m_deletion_has_begun);
+        VERIFY(m_referencing_node_count);
         --m_referencing_node_count;
         if (!m_referencing_node_count && !ref_count()) {
             m_deletion_has_begun = true;

Userland/Libraries/LibWeb/DOM/Element.cpp

@@ -131,7 +131,7 @@ RefPtr<Layout::Node> Element::create_layout_node()
 
     switch (display) {
     case CSS::Display::None:
-        ASSERT_NOT_REACHED();
+        VERIFY_NOT_REACHED();
         break;
     case CSS::Display::Block:
         return adopt(*new Layout::BlockBox(document(), this, move(style)));
@@ -164,7 +164,7 @@ RefPtr<Layout::Node> Element::create_layout_node()
         // FIXME: This is just an incorrect placeholder until we improve table layout support.
         return adopt(*new Layout::BlockBox(document(), this, move(style)));
     }
-    ASSERT_NOT_REACHED();
+    VERIFY_NOT_REACHED();
 }
 
 void Element::parse_attribute(const FlyString& name, const String& value)
@@ -214,7 +214,7 @@ static StyleDifference compute_style_difference(const CSS::StyleProperties& old_
 void Element::recompute_style()
 {
     set_needs_style_update(false);
-    ASSERT(parent());
+    VERIFY(parent());
     auto old_specified_css_values = m_specified_css_values;
     auto new_specified_css_values = document().style_resolver().resolve_style(*this);
     m_specified_css_values = new_specified_css_values;

Userland/Libraries/LibWeb/DOM/EventDispatcher.cpp

@@ -136,7 +136,7 @@ void EventDispatcher::invoke(Event::PathEntry& struct_, Event& event, Event::Pha
         return entry.index <= struct_.index && !entry.shadow_adjusted_target.is_null();
     });
 
-    ASSERT(last_valid_shadow_adjusted_target.has_value());
+    VERIFY(last_valid_shadow_adjusted_target.has_value());
 
     event.set_target(last_valid_shadow_adjusted_target.value().shadow_adjusted_target);
     event.set_related_target(struct_.related_target);
@@ -249,7 +249,7 @@ bool EventDispatcher::dispatch(NonnullRefPtr<EventTarget> target, NonnullRefPtr<
             return !entry.shadow_adjusted_target.is_null();
         });
 
-        ASSERT(clear_targets_struct.has_value());
+        VERIFY(clear_targets_struct.has_value());
 
         if (is<Node>(clear_targets_struct.value().shadow_adjusted_target.ptr())) {
             auto& shadow_adjusted_target_node = downcast<Node>(*clear_targets_struct.value().shadow_adjusted_target);

Userland/Libraries/LibWeb/DOM/EventListener.cpp

@@ -31,7 +31,7 @@ namespace Web::DOM {
 
 JS::Function& EventListener::function()
 {
-    ASSERT(m_function.cell());
+    VERIFY(m_function.cell());
     return *m_function.cell();
 }
 

Userland/Libraries/LibWeb/DOM/Node.cpp

@@ -54,7 +54,7 @@ Node::Node(Document& document, NodeType type)
 
 Node::~Node()
 {
-    ASSERT(m_deletion_has_begun);
+    VERIFY(m_deletion_has_begun);
     if (layout_node() && layout_node()->parent())
         layout_node()->parent()->remove_child(*layout_node());
 

Userland/Libraries/LibWeb/DOM/Window.cpp

@@ -95,7 +95,7 @@ i32 Window::set_timeout(JS::Function& callback, i32 interval)
 void Window::timer_did_fire(Badge<Timer>, Timer& timer)
 {
     // We should not be here if there's no JS wrapper for the Window object.
-    ASSERT(wrapper());
+    VERIFY(wrapper());
     auto& vm = wrapper()->vm();
 
     // NOTE: This protector pointer keeps the timer alive until the end of this function no matter what.