Revert of toBlob: If idle image encoding is postponed for too long, switch to main thread

third_party/WebKit/Source/core/html/canvas/CanvasAsyncBlobCreator.h

Index: third_party/WebKit/Source/core/html/canvas/CanvasAsyncBlobCreator.h
diff --git a/third_party/WebKit/Source/core/html/canvas/CanvasAsyncBlobCreator.h b/third_party/WebKit/Source/core/html/canvas/CanvasAsyncBlobCreator.h
index 0ac104d548994a9c6976cdaa0af541dc7d2ad08a..391a9ce9a387789b3fe74163480054a777b39a63 100644
--- a/third_party/WebKit/Source/core/html/canvas/CanvasAsyncBlobCreator.h
+++ b/third_party/WebKit/Source/core/html/canvas/CanvasAsyncBlobCreator.h
@@ -5,7 +5,6 @@
 #include "core/CoreExport.h"
 #include "core/dom/DOMTypedArray.h"
 #include "core/fileapi/BlobCallback.h"
-#include "platform/Task.h"
 #include "platform/geometry/IntSize.h"
 #include "platform/heap/Handle.h"
 #include "wtf/OwnPtr.h"
@@ -24,32 +23,11 @@
     static PassRefPtr<CanvasAsyncBlobCreator> create(PassRefPtr<DOMUint8ClampedArray> unpremultipliedRGBAImageData, const String& mimeType, const IntSize&, BlobCallback*);
     void scheduleAsyncBlobCreation(bool canUseIdlePeriodScheduling, double quality = 0.0);
     virtual ~CanvasAsyncBlobCreator();
-    enum IdleTaskStatus {
-        IdleTaskNotStarted,
-        IdleTaskStarted,
-        IdleTaskCompleted,
-        IdleTaskFailed,
-        IdleTaskSwitchedToMainThreadTask,
-        Default // Idle tasks are not implemented for some image types
-    };
-    virtual void signalTaskSwitchInStartTimeoutEventForTesting() { }
-    virtual void signalTaskSwitchInCompleteTimeoutEventForTesting() { }
-
-protected:
-    CanvasAsyncBlobCreator(PassRefPtr<DOMUint8ClampedArray> data, const String& mimeType, const IntSize&, BlobCallback*);
-    virtual void scheduleInitiatePngEncoding();
-    virtual void idleEncodeRowsPng(double deadlineSeconds);
-    virtual void postDelayedTaskToMainThread(const WebTraceLocation&, Task*, double delayMs);
-    virtual void clearAlternativeSelfReference();
-    virtual void createBlobAndCall();
-    virtual void createNullptrAndCall();
-
-    void clearSelfReference();
-    void initiatePngEncoding(double deadlineSeconds);
-    IdleTaskStatus m_idleTaskStatus;
 
 private:
-    friend class CanvasAsyncBlobCreatorTest;
+    CanvasAsyncBlobCreator(PassRefPtr<DOMUint8ClampedArray> data, const String& mimeType, const IntSize&, BlobCallback*);
+    void scheduleCreateBlobAndCallOnMainThread();
+    void scheduleCreateNullptrAndCallOnMainThread();
 
     OwnPtr<PNGImageEncoderState> m_pngEncoderState;
     OwnPtr<JPEGImageEncoderState> m_jpegEncoderState;
@@ -62,22 +40,18 @@
     const String m_mimeType;
     CrossThreadPersistent<BlobCallback> m_callback;
 
-    // To keep this asyncBlobCreator alive before async encoding task completes
-    // Used by all image types
     RefPtr<CanvasAsyncBlobCreator> m_selfRef;
-    // To keep this asyncBlobCreator alive before the alternative code path (for
-    // the case when idle task is postponed for too long) is confirmed not to
-    // continue any more; Used by png image type only
-    RefPtr<CanvasAsyncBlobCreator> m_alternativeSelfRef;
+    void clearSelfReference();
 
-    bool initializePngStruct();
-    void encodeRowsPngOnMainThread(); // Similar to idleEncodeRowsPng without deadline
-    void encodeImageOnEncoderThread(double quality);
+    void initiatePngEncoding(double deadlineSeconds);
+    void scheduleIdleEncodeRowsPng();
+    void idleEncodeRowsPng(double deadlineSeconds);
 
     void initiateJpegEncoding(const double& quality);
 
-    void idleTaskStartTimeoutEvent(double quality);
-    void idleTaskCompleteTimeoutEvent();
+    void createBlobAndCall();
+
+    void encodeImageOnEncoderThread(double quality);
 };
 
 } // namespace blink