Register clipboard image blob in the browser process to copy data less.

third_party/WebKit/Source/core/clipboard/DataObjectItem.cpp

 /*
  * Copyright (C) 2011 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
@@ skipping 98 matching lines @@
             return m_file.get();
         ASSERT(m_sharedBuffer);
         // FIXME: This code is currently impossible--we never populate m_sharedBuffer when dragging
         // in. At some point though, we may need to support correctly converting a shared buffer
         // into a file.
         return nullptr;
     }
 
     ASSERT(m_source == PasteboardSource);
     if (type() == mimeTypeImagePng) {
-        // FIXME: This is pretty inefficient. We copy the data from the browser
-        // to the renderer. We then place it in a blob in WebKit, which
-        // registers it and copies it *back* to the browser. When a consumer
-        // wants to read the data, we then copy the data back into the renderer.
-        // https://bugs.webkit.org/show_bug.cgi?id=58107 has been filed to track
-        // improvements to this code (in particular, add a registerClipboardBlob
-        // method to the blob registry; that way the data is only copied over
-        // into the renderer when it's actually read, not when the blob is
-        // initially constructed).
-        RefPtr<SharedBuffer> data = static_cast<PassRefPtr<SharedBuffer>>(Platform::current()->clipboard()->readImage(WebClipboard::BufferStandard));
-        OwnPtr<BlobData> blobData = BlobData::create();
-        blobData->appendBytes(data->data(), data->size());
-        blobData->setContentType(mimeTypeImagePng);
-        return Blob::create(BlobDataHandle::create(blobData.release(), data->size()));
+        WebBlobInfo blobInfo = Platform::current()->clipboard()->readImage(WebClipboard::BufferStandard);
+        if (blobInfo.size() < 0)
+            return nullptr;
+        return Blob::create(BlobDataHandle::create(blobInfo.uuid(), blobInfo.type(), blobInfo.size()));
     }
 
     return nullptr;
 }
 
 String DataObjectItem::getAsString() const
 {
     ASSERT(m_kind == StringKind);
 
     if (m_source == InternalSource)
@@ skipping 23 matching lines @@
     // we'll need to make sure this works as expected for DragDataChromium.
     return m_kind == FileKind && m_file;
 }
 
 DEFINE_TRACE(DataObjectItem)
 {
     visitor->trace(m_file);
 }
 
 } // namespace blink