Fix dropping images into content editable divs.

ui/base/dragdrop/cocoa_dnd_util.h

Index: ui/base/dragdrop/cocoa_dnd_util.h
diff --git a/ui/base/dragdrop/cocoa_dnd_util.h b/ui/base/dragdrop/cocoa_dnd_util.h
index 66ed1a21b84dd63530731607c888bffeb2e47463..8b4d116b2ce2b3cbfdcd606092d88296831bfac3 100644
--- a/ui/base/dragdrop/cocoa_dnd_util.h
+++ b/ui/base/dragdrop/cocoa_dnd_util.h
@@ -22,6 +22,13 @@ namespace ui {
 // associated with it.
 UI_EXPORT extern NSString* const kChromeDragDummyPboardType;
 
+// Mail.app and TextEdit accept drags that have both HTML and image flavors on
+// them, but don't process them correctly <http://crbug.com/55879>. Therefore,
+// if there is an image flavor, don't put the HTML data on as HTML, but rather
+// put it on as this Chrome-only flavor. External apps won't see HTML but
+// Chrome will know enough to read it as HTML. <http://crbug.com/55879>
+UI_EXPORT extern NSString* const kChromeDragImageHTMLPboardType;
+
 // Populates the |url| and |title| with URL data in |pboard|. There may be more
 // than one, but we only handle dropping the first. |url| must not be |NULL|;
 // |title| is an optional parameter. Returns |YES| if URL data was obtained from