Use DEFINE_STATIC_LOCAL in CSSProperty::GetPropertyNameAtomicString

This avoids having a destructor being run when terminating the process.
These destructor could have ordering issues wrt to the destruction of
the AtomicStringTable. Using DEFINE_STATIC_LOCAL also shrinks the binary
a bit. (The android-binary-size bot says -16375 bytes.)

Remove some redundant '\0' characters for some additional (but minor)
savings.

Change-Id: I4f5c19fceb9b668e74d3ef9bad58b104182ddb86
Reviewed-on: https://chromium-review.googlesource.com/1233700Reviewed-by: Anders Ruud <andruud@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#592383}

third_party/blink/renderer/build/scripts/core/css/properties/templates/css_property_subclass.h.tmpl

@@ -38,13 +38,13 @@ class {{property_classname}} final : public {{property.namespace_group}} {
     return RuntimeEnabledFeatures::{{property.runtime_flag}}Enabled();
   }
   {% endif %}
-  const char* GetPropertyName() const override { return "{{property.name}}\0"; }
+  const char* GetPropertyName() const override { return "{{property.name}}"; }
   const WTF::AtomicString& GetPropertyNameAtomicString() const override {
-    static const WTF::AtomicString& name = WTF::AtomicString("{{property.name}}\0");
+    DEFINE_STATIC_LOCAL(const AtomicString, name, ("{{property.name}}"));
     return name;
   }
   const WTF::String GetJSPropertyName() const override {
-    return WTF::String("{{property_classname[0].lower() + property_classname[1:]}}\0");
+    return WTF::String("{{property_classname[0].lower() + property_classname[1:]}}");
   }
   {% if property.alias_for == None %}
   CSSPropertyID PropertyID() const override { return {{property.property_id}}; }

third_party/blink/renderer/core/css/properties/longhands/variable.h

@@ -20,9 +20,9 @@ class Variable final : public Longhand {
   bool IsInherited() const override { return true; }
   bool IsAffectedByAll() const override { return false; }
   CSSPropertyID PropertyID() const override { return CSSPropertyVariable; }
-  const char* GetPropertyName() const override { return "variable\0"; }
+  const char* GetPropertyName() const override { return "variable"; }
   const WTF::AtomicString& GetPropertyNameAtomicString() const override {
-    static const WTF::AtomicString& name = WTF::AtomicString("variable\0");
+    DEFINE_STATIC_LOCAL(const AtomicString, name, ("variable"));
     return name;
   }
   const CSSValue* CSSValueFromComputedStyleInternal(