ozone/wayland: Avoid unneeded subsequent xdg-decoration set_mode requests

xdg-decoration spec says:

 > [...] clients are responsible for preventing configure loops and
 > must make sure not to send multiple successive set_mode requests
 > with the same decoration mode.

which wasn't being done so far and issues like crbug.com/1131662 were
observed. This patch fixes it by avoiding re-sending subsequent set_mode
requests with the same decoration mode.

Additionally a few cleanups and style fixes are made.

R=msisov@igalia.com

Bug: 1131662
Change-Id: I7cb64557775fa8562284067fb90d8cba0dea5d84
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2436851Reviewed-by: Antonio Gomes (GMT-4) <tonikitoo@igalia.com>
Reviewed-by: Abhijeet Kandalkar <abhijeet@igalia.com>
Reviewed-by: Maksim Sisov (GMT+3) <msisov@igalia.com>
Commit-Queue: Nick Yamane <nickdiego@igalia.com>
Cr-Commit-Position: refs/heads/master@{#811600}

ui/ozone/platform/wayland/host/xdg_surface_wrapper_impl.cc

@@ -4,6 +4,7 @@
 
 #include "ui/ozone/platform/wayland/host/xdg_surface_wrapper_impl.h"
 
+#include <xdg-decoration-unstable-v1-client-protocol.h>
 #include <xdg-shell-client-protocol.h>
 #include <xdg-shell-unstable-v6-client-protocol.h>
 
@@ -205,7 +206,10 @@ void XDGSurfaceWrapperImpl::CloseTopLevelStable(
 
 void XDGSurfaceWrapperImpl::SetTopLevelDecorationMode(
     zxdg_toplevel_decoration_v1_mode requested_mode) {
-  zxdg_toplevel_decoration_mode_ = requested_mode;
+  if (requested_mode == decoration_mode_)
+    return;
+
+  decoration_mode_ = requested_mode;
   zxdg_toplevel_decoration_v1_set_mode(zxdg_toplevel_decoration_.get(),
                                        requested_mode);
 }

ui/ozone/platform/wayland/host/xdg_surface_wrapper_impl.h

@@ -9,7 +9,9 @@
 
 #include <xdg-decoration-unstable-v1-client-protocol.h>
 
-#include "base/macros.h"
+#include <cstdint>
+#include <string>
+
 #include "base/strings/string16.h"
 #include "ui/ozone/platform/wayland/common/wayland_object.h"
 
@@ -27,6 +29,8 @@ class XDGSurfaceWrapperImpl : public ShellSurfaceWrapper {
  public:
   XDGSurfaceWrapperImpl(WaylandWindow* wayland_window,
                         WaylandConnection* connection);
+  XDGSurfaceWrapperImpl(const XDGSurfaceWrapperImpl&) = delete;
+  XDGSurfaceWrapperImpl& operator=(const XDGSurfaceWrapperImpl&) = delete;
   ~XDGSurfaceWrapperImpl() override;
 
   // ShellSurfaceWrapper overrides:
@@ -103,9 +107,11 @@ class XDGSurfaceWrapperImpl : public ShellSurfaceWrapper {
   wl::Object<zxdg_toplevel_decoration_v1> zxdg_toplevel_decoration_;
 
   bool surface_for_popup_ = false;
-  enum zxdg_toplevel_decoration_v1_mode zxdg_toplevel_decoration_mode_;
 
-  DISALLOW_COPY_AND_ASSIGN(XDGSurfaceWrapperImpl);
+  // Keeps track of the decoration mode currently in use if xdg-decoration
+  // protocol extension is available, otherwise CLIENT_SIDE is assumed.
+  enum zxdg_toplevel_decoration_v1_mode decoration_mode_ =
+      ZXDG_TOPLEVEL_DECORATION_V1_MODE_CLIENT_SIDE;
 };
 
 }  // namespace ui