Revert 109528 - Use XFixes to update the clipboard sequence number.

ui/base/clipboard/clipboard_gtk.cc

Index: ui/base/clipboard/clipboard_gtk.cc
===================================================================
--- ui/base/clipboard/clipboard_gtk.cc	(revision 109529)
+++ ui/base/clipboard/clipboard_gtk.cc	(working copy)
@@ -5,8 +5,6 @@
 #include "ui/base/clipboard/clipboard.h"
 
 #include <gtk/gtk.h>
-#include <X11/extensions/Xfixes.h>
-#include <X11/Xatom.h>
 #include <map>
 #include <set>
 #include <string>
@@ -14,11 +12,9 @@
 
 #include "base/file_path.h"
 #include "base/logging.h"
-#include "base/memory/singleton.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/utf_string_conversions.h"
 #include "third_party/skia/include/core/SkBitmap.h"
-#include "ui/base/gtk/gtk_signal.h"
-#include "ui/base/x/x11_util.h"
 #include "ui/gfx/canvas_skia.h"
 #include "ui/gfx/gtk_util.h"
 #include "ui/gfx/size.h"
@@ -27,82 +23,6 @@
 
 namespace {
 
-class SelectionChangeObserver {
- public:
-  static SelectionChangeObserver* GetInstance();
-
-  uint64 clipboard_sequence_number() const {
-    return clipboard_sequence_number_;
-  }
-  uint64 primary_sequence_number() const { return primary_sequence_number_; }
-
- private:
-  friend struct DefaultSingletonTraits<SelectionChangeObserver>;
-
-  SelectionChangeObserver();
-  ~SelectionChangeObserver();
-
-  CHROMEG_CALLBACK_1(SelectionChangeObserver, GdkFilterReturn, OnXEvent,
-                     GdkXEvent*, GdkEvent*);
-
-  int event_base_;
-  Atom clipboard_atom_;
-  uint64 clipboard_sequence_number_;
-  uint64 primary_sequence_number_;
-
-  DISALLOW_COPY_AND_ASSIGN(SelectionChangeObserver);
-};
-
-SelectionChangeObserver::SelectionChangeObserver()
-    : event_base_(-1),
-      clipboard_atom_(None),
-      clipboard_sequence_number_(0),
-      primary_sequence_number_(0) {
-  int ignored;
-  if (XFixesQueryExtension(GetXDisplay(), &event_base_, &ignored)) {
-    clipboard_atom_ = XInternAtom(GetXDisplay(), "CLIPBOARD", false);
-    XFixesSelectSelectionInput(GetXDisplay(), GetX11RootWindow(),
-                               clipboard_atom_,
-                               XFixesSetSelectionOwnerNotifyMask |
-                               XFixesSelectionWindowDestroyNotifyMask |
-                               XFixesSelectionClientCloseNotifyMask);
-    // This seems to be semi-optional. For some reason, registering for any
-    // selection notify events seems to subscribe us to events for both the
-    // primary and the clipboard buffers. Register anyway just to be safe.
-    XFixesSelectSelectionInput(GetXDisplay(), GetX11RootWindow(),
-                               XA_PRIMARY,
-                               XFixesSetSelectionOwnerNotifyMask |
-                               XFixesSelectionWindowDestroyNotifyMask |
-                               XFixesSelectionClientCloseNotifyMask);
-    gdk_window_add_filter(NULL, &SelectionChangeObserver::OnXEventThunk, this);
-  }
-}
-
-SelectionChangeObserver::~SelectionChangeObserver() {
-}
-
-SelectionChangeObserver* SelectionChangeObserver::GetInstance() {
-  return Singleton<SelectionChangeObserver>::get();
-}
-
-GdkFilterReturn SelectionChangeObserver::OnXEvent(GdkXEvent* xevent,
-                                                  GdkEvent* event) {
-  XEvent* xev = static_cast<XEvent*>(xevent);
-
-  if (xev->type == event_base_ + XFixesSelectionNotify) {
-    XFixesSelectionNotifyEvent* ev =
-        reinterpret_cast<XFixesSelectionNotifyEvent*>(xev);
-    if (ev->selection == clipboard_atom_) {
-      clipboard_sequence_number_++;
-    } else if (ev->selection == XA_PRIMARY) {
-      primary_sequence_number_++;
-    } else {
-      DLOG(ERROR) << "Unexpected selection atom: " << ev->selection;
-    }
-  }
-  return GDK_FILTER_CONTINUE;
-}
-
 const char kMimeTypeBitmap[] = "image/bmp";
 const char kMimeTypeMozillaURL[] = "text/x-moz-url";
 const char kMimeTypeWebkitSmartPaste[] = "chromium/x-webkit-paste";
@@ -503,10 +423,10 @@
 }
 
 uint64 Clipboard::GetSequenceNumber(Buffer buffer) {
-  if (buffer == BUFFER_STANDARD)
-    return SelectionChangeObserver::GetInstance()->clipboard_sequence_number();
-  else
-    return SelectionChangeObserver::GetInstance()->primary_sequence_number();
+  // TODO(cdn): implement this. For now this interface will advertise
+  // that the Linux clipboard never changes. That's fine as long as we
+  // don't rely on this signal.
+  return 0;
 }
 
 // static