make a static-only class for DOMWindowTimers instead of namespace

Namespace should be lower-cased. DOMWindowTimers Namespace also
should be lower-cased,
and it is used to [ImplementedAs] to implement WindowTimers.
According to Blink IDL extended attributes[1],
it doesn't mention class name's rule.
so it looks like not violate to use snake_case in any rules.

However this CL makes DOMWindowTimers a static-only class
because ImplementedAs=dom_window_timers is inconsistent
with other ImplementedAs instances.

This CL has no behavior changes.

[1]https://chromium.googlesource.com/chromium/src/+/HEAD/third_party/blink/renderer/bindings/IDLExtendedAttributes.md#ImplementedAs_i_m_s_a

Bug: None
Change-Id: Ia1d7305ebc28feb0c50d6b406ab381998959038e
Reviewed-on: https://chromium-review.googlesource.com/c/1307533
Commit-Queue: Hwanseung Lee <hs1217.lee@samsung.com>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605231}

third_party/blink/renderer/core/frame/dom_window_timers.cc

@@ -46,8 +46,6 @@
 
 namespace blink {
 
-namespace DOMWindowTimers {
-
 static bool IsAllowed(ScriptState* script_state,
                       ExecutionContext* execution_context,
                       bool is_eval,
@@ -82,7 +80,7 @@ static bool IsAllowed(ScriptState* script_state,
   return false;
 }
 
-int setTimeout(ScriptState* script_state,
+int DOMWindowTimers::setTimeout(ScriptState* script_state,
                                 EventTarget& event_target,
                                 const ScriptValue& handler,
                                 int timeout,
@@ -101,7 +99,8 @@ int setTimeout(ScriptState* script_state,
                            TimeDelta::FromMilliseconds(timeout), true);
 }
 
-int setTimeout(ScriptState* script_state,
+int DOMWindowTimers::setTimeout(
+    ScriptState* script_state,
     EventTarget& event_target,
     const StringOrTrustedScript& string_or_trusted_script,
     int timeout,
@@ -119,7 +118,7 @@ int setTimeout(ScriptState* script_state,
                               arguments);
 }
 
-int setTimeoutFromString(ScriptState* script_state,
+int DOMWindowTimers::setTimeoutFromString(ScriptState* script_state,
                                           EventTarget& event_target,
                                           const String& handler,
                                           int timeout,
@@ -142,7 +141,7 @@ int setTimeoutFromString(ScriptState* script_state,
                            TimeDelta::FromMilliseconds(timeout), true);
 }
 
-int setInterval(ScriptState* script_state,
+int DOMWindowTimers::setInterval(ScriptState* script_state,
                                  EventTarget& event_target,
                                  const ScriptValue& handler,
                                  int timeout,
@@ -156,7 +155,8 @@ int setInterval(ScriptState* script_state,
                            TimeDelta::FromMilliseconds(timeout), false);
 }
 
-int setInterval(ScriptState* script_state,
+int DOMWindowTimers::setInterval(
+    ScriptState* script_state,
     EventTarget& event_target,
     const StringOrTrustedScript& string_or_trusted_script,
     int timeout,
@@ -174,7 +174,7 @@ int setInterval(ScriptState* script_state,
                                arguments);
 }
 
-int setIntervalFromString(ScriptState* script_state,
+int DOMWindowTimers::setIntervalFromString(ScriptState* script_state,
                                            EventTarget& event_target,
                                            const String& handler,
                                            int timeout,
@@ -192,16 +192,14 @@ int setIntervalFromString(ScriptState* script_state,
                            TimeDelta::FromMilliseconds(timeout), false);
 }
 
-void clearTimeout(EventTarget& event_target, int timeout_id) {
+void DOMWindowTimers::clearTimeout(EventTarget& event_target, int timeout_id) {
   if (ExecutionContext* context = event_target.GetExecutionContext())
     DOMTimer::RemoveByID(context, timeout_id);
 }
 
-void clearInterval(EventTarget& event_target, int timeout_id) {
+void DOMWindowTimers::clearInterval(EventTarget& event_target, int timeout_id) {
   if (ExecutionContext* context = event_target.GetExecutionContext())
     DOMTimer::RemoveByID(context, timeout_id);
 }
 
-}  // namespace DOMWindowTimers
-
 }  // namespace blink

third_party/blink/renderer/core/frame/dom_window_timers.h

@@ -33,6 +33,7 @@
 #ifndef THIRD_PARTY_BLINK_RENDERER_CORE_FRAME_DOM_WINDOW_TIMERS_H_
 #define THIRD_PARTY_BLINK_RENDERER_CORE_FRAME_DOM_WINDOW_TIMERS_H_
 
+#include "third_party/blink/renderer/platform/wtf/allocator.h"
 #include "third_party/blink/renderer/platform/wtf/forward.h"
 #include "third_party/blink/renderer/platform/wtf/vector.h"
 
@@ -44,42 +45,45 @@ class ScriptState;
 class ScriptValue;
 class StringOrTrustedScript;
 
-namespace DOMWindowTimers {
-int setTimeout(ScriptState*,
+class DOMWindowTimers {
+  STATIC_ONLY(DOMWindowTimers);
+
+ public:
+  static int setTimeout(ScriptState*,
                         EventTarget&,
                         const ScriptValue& handler,
                         int timeout,
                         const Vector<ScriptValue>& arguments);
-int setTimeout(ScriptState*,
+  static int setTimeout(ScriptState*,
                         EventTarget&,
                         const StringOrTrustedScript&,
                         int timeout,
                         const Vector<ScriptValue>&,
                         ExceptionState&);
-int setTimeoutFromString(ScriptState*,
+  static int setTimeoutFromString(ScriptState*,
                                   EventTarget&,
                                   const String& handler,
                                   int timeout,
                                   const Vector<ScriptValue>&);
-int setInterval(ScriptState*,
+  static int setInterval(ScriptState*,
                          EventTarget&,
                          const ScriptValue& handler,
                          int timeout,
                          const Vector<ScriptValue>&);
-int setInterval(ScriptState*,
+  static int setInterval(ScriptState*,
                          EventTarget&,
                          const StringOrTrustedScript&,
                          int timeout,
                          const Vector<ScriptValue>&,
                          ExceptionState&);
-int setIntervalFromString(ScriptState*,
+  static int setIntervalFromString(ScriptState*,
                                    EventTarget&,
                                    const String& handler,
                                    int timeout,
                                    const Vector<ScriptValue>&);
-void clearTimeout(EventTarget&, int timeout_id);
-void clearInterval(EventTarget&, int timeout_id);
-}
+  static void clearTimeout(EventTarget&, int timeout_id);
+  static void clearInterval(EventTarget&, int timeout_id);
+};
 
 }  // namespace blink