Revert of Canvas.toDataURL to use SkBitmap::readPixels to avoid uninitialized memory

Source/core/html/HTMLCanvasElement.cpp

Index: Source/core/html/HTMLCanvasElement.cpp
diff --git a/Source/core/html/HTMLCanvasElement.cpp b/Source/core/html/HTMLCanvasElement.cpp
index a6b3d958f42631f5ebcfa7fbb1413c2180284ed3..a41bd5beb6c08ff3077a3349eed785e68b5293e3 100644
--- a/Source/core/html/HTMLCanvasElement.cpp
+++ b/Source/core/html/HTMLCanvasElement.cpp
@@ -463,43 +463,28 @@
     return AtomicString(toDataURLInternal("image/png", 0, FrontBuffer));
 }
 
-ImageData* HTMLCanvasElement::toImageData(SourceDrawingBuffer sourceBuffer) const
-{
-    ImageData* imageData;
-    if (is3D()) {
-        // Get non-premultiplied data because of inaccurate premultiplied alpha conversion of buffer()->toDataURL().
-        imageData = m_context->paintRenderingResultsToImageData(sourceBuffer);
-        if (imageData)
-            return imageData;
-
-        m_context->paintRenderingResultsToCanvas(sourceBuffer);
-        imageData = ImageData::create(m_size);
-        SkImageInfo imageInfo = SkImageInfo::Make(width(), height(), kRGBA_8888_SkColorType, kUnpremul_SkAlphaType);
-        buffer()->bitmap().readPixels(imageInfo, imageData->data()->data(), imageInfo.minRowBytes(), 0, 0);
-        return imageData;
-    }
-
-    imageData = ImageData::create(m_size);
-
-    if (m_context) {
-        ASSERT(m_context->is2d());
-        SkImageInfo imageInfo = SkImageInfo::Make(width(), height(), kRGBA_8888_SkColorType, kUnpremul_SkAlphaType);
-        buffer()->bitmap().readPixels(imageInfo, imageData->data()->data(), imageInfo.minRowBytes(), 0, 0);
-    }
-    return imageData;
-}
-
 String HTMLCanvasElement::toDataURLInternal(const String& mimeType, const double* quality, SourceDrawingBuffer sourceBuffer) const
 {
     if (!isPaintable())
         return String("data:,");
 
     String encodingMimeType = toEncodingMimeType(mimeType);
-
-    ImageData* imageData = toImageData(sourceBuffer);
-    ScopedDisposal<ImageData> disposer(imageData);
-
-    return ImageDataBuffer(imageData->size(), imageData->data()->data()).toDataURL(encodingMimeType, quality);
+    if (!m_context) {
+        ImageData* imageData = ImageData::create(m_size);
+        ScopedDisposal<ImageData> disposer(imageData);
+        return ImageDataBuffer(imageData->size(), imageData->data()->data()).toDataURL(encodingMimeType, quality);
+    }
+
+    if (m_context->is3d()) {
+        // Get non-premultiplied data because of inaccurate premultiplied alpha conversion of buffer()->toDataURL().
+        ImageData* imageData = m_context->paintRenderingResultsToImageData(sourceBuffer);
+        ScopedDisposal<ImageData> disposer(imageData);
+        if (imageData)
+            return ImageDataBuffer(imageData->size(), imageData->data()->data()).toDataURL(encodingMimeType, quality);
+        m_context->paintRenderingResultsToCanvas(sourceBuffer);
+    }
+
+    return buffer()->toDataURL(encodingMimeType, quality);
 }
 
 String HTMLCanvasElement::toDataURL(const String& mimeType, const ScriptValue& qualityArgument, ExceptionState& exceptionState) const