Adds a WebPageScheduler and a WebFrameScheduler

These APIs are intended to support spatial scheduling and task attribution.

Chromium implementation: https://codereview.chromium.org/1314903007/

BUG=510398

Review URL: https://codereview.chromium.org/1316233010

git-svn-id: svn://svn.chromium.org/blink/trunk@201978 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/public/BUILD.gn

@@ -131,6 +131,8 @@ source_set("blink_headers") {
     "platform/WebMediaStream.h",
     "platform/WebServiceWorkerRegistration.h",
     "platform/WebRect.h",
+    "platform/WebPageScheduler.h",
+    "platform/WebFrameScheduler.h",
     "platform/WebTaskRunner.h",
     "platform/WebThread.h",
     "platform/WebSetSinkIdError.h",

third_party/WebKit/public/platform/WebFrameScheduler.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef WebFrameScheduler_h
+#define WebFrameScheduler_h
+
+#include "WebCommon.h"
+
+#include <string>
+
+namespace blink {
+
+class WebSecurityOrigin;
+class WebTaskRunner;
+
+class BLINK_PLATFORM_EXPORT WebFrameScheduler {
+public:
+    virtual ~WebFrameScheduler() { }
+
+    // The scheduler may throttle tasks associated with offscreen frames.
+    virtual void setFrameVisible(bool) { }
+
+    // Returns the WebTaskRunner for loading tasks.
+    // WebFrameScheduler owns the returned WebTaskRunner.
+    virtual WebTaskRunner* loadingTaskRunner() { return nullptr; }
+
+    // Returns the WebTaskRunner for timer tasks.
+    // WebFrameScheduler owns the returned WebTaskRunner.
+    virtual WebTaskRunner* timerTaskRunner() { return nullptr; }
+
+    // Record the current origin. This is for task attribution in tracing.
+    virtual void setFrameOrigin(const WebSecurityOrigin*) { }
+};
+
+} // namespace blink
+
+#endif // WebFrameScheduler_h

third_party/WebKit/public/platform/WebPageScheduler.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef WebPageScheduler_h
+#define WebPageScheduler_h
+
+#include "WebCommon.h"
+
+namespace blink {
+
+class WebFrameScheduler;
+
+class BLINK_PLATFORM_EXPORT WebPageScheduler {
+public:
+    virtual ~WebPageScheduler() { }
+
+    // The scheduler may throttle tasks associated with backgound pages.
+    virtual void setPageInBackground(bool) { }
+
+    // Creaters a new WebFrameScheduler, the caller is responsible for deleting it.
+    WebFrameScheduler* createFrameScheduler() { return nullptr; }
+};
+
+} // namespace blink
+
+#endif // WebPageScheduler_h

third_party/WebKit/public/platform/WebScheduler.h

@@ -11,6 +11,7 @@
 
 namespace blink {
 
+class WebPageScheduler;
 class WebTraceLocation;
 
 // This class is used to submit tasks and pass other information from Blink to
@@ -72,6 +73,9 @@ public:
     // Returns a WebTaskRunner for timer tasks. Can be called from any thread.
     virtual WebTaskRunner* timerTaskRunner() { return nullptr; }
 
+    // Creates a new WebPageScheduler. Must be called from the associated WebThread.
+    virtual WebPageScheduler* createPageScheduler() { return nullptr; }
+
     // Suspends the timer queue and increments the timer queue suspension count.
     // May only be called from the main thread.
     virtual void suspendTimerQueue() { }