Revert of Remove V8RecrusionScope, cleanup call sites. (patchset #8 id:140001 of https://codereview…

third_party/WebKit/public/web/WebScopedMicrotaskSuppression.h

 /*
- * Copyright (C) 2011 Google Inc. All rights reserved.
+ * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
  * copyright notice, this list of conditions and the following disclaimer
  * in the documentation and/or other materials provided with the
  * distribution.
  *     * Neither the name of Google Inc. nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef WebScopedUserGesture_h
-#define WebScopedUserGesture_h
+#ifndef WebScopedMicrotaskSuppression_h
+#define WebScopedMicrotaskSuppression_h
 
 #include "../platform/WebPrivateOwnPtr.h"
 
 namespace blink {
 
-class UserGestureIndicator;
-class WebUserGestureToken;
-
-// An instance of this class, while kept alive, will indicate that we are in
-// the context of a known user gesture. To use, create one, perform whatever
-// actions were done under color of a known user gesture, and then delete it.
-// Usually this will be done on the stack.
+// This class wraps V8RecursionScope::BypassMicrotaskCheckpoint. Please
+// see V8RecursionScope.h for full usage. Short story: Embedder calls into
+// script contexts which also host page script must do one of two things:
 //
-// SECURITY WARNING: Do not create several instances of this class for the same
-// user gesture. Doing so might enable malicious code to work around certain
-// restrictions such as opening multiple windows.
-// Instead, obtain the current WebUserGestureToken from the
-// WebUserGestureIndicator, and use this token to create a
-// WebScopedUserGesture. If the token was alrady consumed, the new
-// WebScopedUserGesture will not indicate that we are in the context of a user
-// gesture.
-class WebScopedUserGesture {
+//   1. If the call may cause any page/author script to run, it must be
+//      captured for pre/post work (e.g. inspector instrumentation/microtask
+//      delivery) and thus be invoked through WebFrame (e.g. executeScript*,
+//      callFunction*).
+//   2. If the call will not cause any page/author script to run, the call
+//      should be made directly via the v8 context, but the callsite must be
+//      accompanied by a stack allocated WebScopedMicrotaskSuppression, e.g.:
+//
+//        ...
+//        {
+//            blink::WebScopedMicrotaskSuppression suppression;
+//            func->Call(global, argv, args);
+//        }
+//        ...
+//
+class WebScopedMicrotaskSuppression {
 public:
-    explicit WebScopedUserGesture(const WebUserGestureToken& token) { initializeWithToken(token); }
-    WebScopedUserGesture() { initialize(); }
-    ~WebScopedUserGesture() { reset(); }
+    WebScopedMicrotaskSuppression() { initialize(); }
+    ~WebScopedMicrotaskSuppression() { reset(); }
 
 private:
     BLINK_EXPORT void initialize();
-    BLINK_EXPORT void initializeWithToken(const WebUserGestureToken&);
     BLINK_EXPORT void reset();
 
-    WebPrivateOwnPtr<UserGestureIndicator> m_indicator;
+    // Always declare this data member. When assertions are on in
+    // Release builds of Blink, this header may be included from
+    // Chromium with different preprocessor options than used when
+    // building Blink itself.
+    class Impl;
+    WebPrivateOwnPtr<Impl> m_impl;
 };
 
 } // namespace blink
 
-#endif // WebScopedUserGesture_h
+#endif