Basic DragImage implementation....

chrome/browser/gtk/tab_contents_drag_source.cc

Index: chrome/browser/gtk/tab_contents_drag_source.cc
===================================================================
--- chrome/browser/gtk/tab_contents_drag_source.cc	(revision 41111)
+++ chrome/browser/gtk/tab_contents_drag_source.cc	(working copy)
@@ -6,6 +6,7 @@
 
 #include <string>
 
+#include "app/gfx/gtk_util.h"
 #include "app/gtk_dnd_util.h"
 #include "base/file_util.h"
 #include "base/mime_util.h"
@@ -69,7 +70,9 @@
 }
 
 void TabContentsDragSource::StartDragging(const WebDropData& drop_data,
-                                          GdkEventButton* last_mouse_down) {
+                                          GdkEventButton* last_mouse_down,
+                                          const SkBitmap& image,
+                                          const gfx::Point& image_offset) {
   int targets_mask = 0;
 
   if (!drop_data.plain_text.empty())
@@ -98,6 +101,8 @@
   }
 
   drop_data_.reset(new WebDropData(drop_data));
+  drag_image_ = image;
+  image_offset_ = image_offset;
 
   GtkTargetList* list = GtkDndUtil::GetTargetListFromCodeMask(targets_mask);
   if (targets_mask & GtkDndUtil::CHROME_WEBDROP_FILE_CONTENTS) {
@@ -303,6 +308,14 @@
                             generated_download_file_name.value().c_str()),
                         generated_download_file_name.value().length());
   }
+
+  if (!drag_image_.isNull()) {
+    GdkPixbuf* pixbuf = gfx::GdkPixbufFromSkBitmap(&drag_image_);
+    gtk_drag_set_icon_pixbuf(drag_context, pixbuf,
+                             image_offset_.x(), image_offset_.y());
+    // Let the drag take ownership.
+    g_object_unref(pixbuf);
+  }
 }
 
 void TabContentsDragSource::OnDragEnd(GdkDragContext* drag_context,