Fix several memory leaks in gtk_clipboard_dump utility.

tools/gtk_clipboard_dump/gtk_clipboard_dump.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <gtk/gtk.h>
 #include <stdio.h>
 #include <string.h>
+#include <string>
 
 namespace {
 
 void PrintClipboardContents(GtkClipboard* clip) {
   GdkAtom* targets;
   int num_targets = 0;
 
   // This call is bugged, the cache it checks is often stale; see
   // <http://bugzilla.gnome.org/show_bug.cgi?id=557315>.
   // gtk_clipboard_wait_for_targets(clip, &targets, &num_targets);
 
   GtkSelectionData* target_data =
       gtk_clipboard_wait_for_contents(clip,
                                       gdk_atom_intern("TARGETS", false));
   if (!target_data) {
     printf("failed to get the contents!\n");
     return;
   }
 
   gtk_selection_data_get_targets(target_data, &targets, &num_targets);
 
   printf("%d available targets:\n---------------\n", num_targets);
 
   for (int i = 0; i < num_targets; i++) {
-    printf("  [format: %s", gdk_atom_name(targets[i]));
+    gchar* target_name_cstr = gdk_atom_name(targets[i]);
+    std::string target_name(target_name_cstr);
+    g_free(target_name_cstr);
+    printf("  [format: %s", target_name.c_str());
     GtkSelectionData* data = gtk_clipboard_wait_for_contents(clip, targets[i]);
     if (!data) {
       printf("]: NULL\n\n");
       continue;
     }
 
     printf(" / length: %d / bits %d]: ", data->length, data->format);
 
-    if (strstr(gdk_atom_name(targets[i]), "image")) {
+    if (strstr(target_name.c_str(), "image")) {
       printf("(image omitted)\n\n");
-      continue;
-    } else if (strstr(gdk_atom_name(targets[i]), "TIMESTAMP")) {
+    } else if (strstr(target_name.c_str(), "TIMESTAMP")) {
       // TODO(estade): Print the time stamp in human readable format.
       printf("(time omitted)\n\n");
-      continue;
+    } else {
+      for (int j = 0; j < data->length; j++) {
+        // Output data one byte at a time. Currently wide strings look
+        // pretty weird.
+        printf("%c", (data->data[j] == 0 ? '_' : data->data[j]));
+      }
+      printf("\n\n");
     }
-
-    for (int j = 0; j < data->length; j++) {
-      // Output data one byte at a time. Currently wide strings look
-      // pretty weird.
-      printf("%c", (data->data[j] == 0 ? '_' : data->data[j]));
-    }
-    printf("\n\n");
+    gtk_selection_data_free(data);
   }
 
   if (num_targets <= 0) {
     printf("No targets advertised. Text is: ");
     gchar* text = gtk_clipboard_wait_for_text(clip);
     printf("%s\n", text ? text : "NULL");
     g_free(text);
   }
 
   g_free(targets);
+  gtk_selection_data_free(target_data);
 }
 
 }
 
 /* Small program to dump the contents of GTK's clipboards to the terminal.
  * Feel free to add to it or improve formatting or whatnot.
  */
 int main(int argc, char* argv[]) {
   gtk_init(&argc, &argv);
 
   printf("Desktop clipboard\n");
   PrintClipboardContents(gtk_clipboard_get(GDK_SELECTION_CLIPBOARD));
 
   printf("X clipboard\n");
   PrintClipboardContents(gtk_clipboard_get(GDK_SELECTION_PRIMARY));
 }