Revert r78134+r78136

ui/base/clipboard/clipboard_linux.cc

Index: ui/base/clipboard/clipboard_linux.cc
diff --git a/ui/base/clipboard/clipboard_linux.cc b/ui/base/clipboard/clipboard_linux.cc
index 3bb1e888075c2cb37cb3e8e6b423c9152a2cd365..f9ec174418c83a798a2bcf28d249d13ac4b8ff9f 100644
--- a/ui/base/clipboard/clipboard_linux.cc
+++ b/ui/base/clipboard/clipboard_linux.cc
@@ -360,15 +360,6 @@ void Clipboard::ReadHTML(Clipboard::Buffer buffer, string16* markup,
   gtk_selection_data_free(data);
 }
 
-void Clipboard::ReadImage(Buffer buffer, std::string* data) const {
-  // TODO(dcheng): implement this.
-  NOTIMPLEMENTED();
-  if (!data) {
-    NOTREACHED();
-    return;
-  }
-}
-
 void Clipboard::ReadBookmark(string16* title, std::string* url) const {
   // TODO(estade): implement this.
   NOTIMPLEMENTED();