Port xwmstartupcheck to XProto

This removes all usage of Xlib except for ConnectionNumber.

R=msisov

Bug: 1066670
Change-Id: Ic714254bfda1fc2087c089dbe471b92e3b4c4915
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2373186
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Maksim Sisov (GMT+3) <msisov@igalia.com>
Cr-Commit-Position: refs/heads/master@{#801410}

ui/base/x/xwmstartupcheck/BUILD.gn

@@ -7,7 +7,10 @@ executable("xwmstartupcheck") {
 
   sources = [ "xwmstartupcheck.cc" ]
 
-  deps = [ "//base" ]
+  deps = [
+    "//base",
+    "//ui/gfx/x",
+  ]
 
   configs += [ "//build/config/linux:x11" ]
 }

ui/base/x/xwmstartupcheck/xwmstartupcheck.cc

@@ -7,12 +7,15 @@
 // BEFORE the Wm starts.
 //
 
+#include <time.h>
+
 #include <cerrno>
 #include <cstdio>
 
-#include <time.h>
-
-#include <X11/Xlib.h>
+#include "base/command_line.h"
+#include "ui/gfx/x/connection.h"
+#include "ui/gfx/x/x11.h"
+#include "ui/gfx/x/xproto.h"
 
 void CalculateTimeout(const timespec& now,
                       const timespec& deadline,
@@ -24,53 +27,37 @@ void CalculateTimeout(const timespec& now,
   timeout->tv_sec = 0;
 }
 
-class XScopedDisplay {
- public:
-  explicit XScopedDisplay(Display* display) : display_(display) {}
-  ~XScopedDisplay() {
-    if (display_)
-      XCloseDisplay(display_);
-  }
-
-  Display* display() const { return display_; }
-
- private:
-  Display* const display_;
-};
-
 int main(int argc, char* argv[]) {
-  // Connects to a display specified in the current process' env value DISPLAY.
-  XScopedDisplay scoped_display(XOpenDisplay(nullptr));
-
-  // No display found - fail early.
-  if (!scoped_display.display()) {
-    fprintf(stderr, "Couldn't connect to a display.\n");
-    return 1;
-  }
+  base::CommandLine::Init(argc, argv);
 
-  auto* xdisplay = scoped_display.display();
+  // Connects to a X server specified in the current process' env value DISPLAY.
+  x11::Connection connection;
 
-  auto root_window = DefaultRootWindow(xdisplay);
-  if (!root_window) {
-    fprintf(stderr, "Couldn't find root window.\n");
+  // No display found - fail early.
+  if (!connection.Ready()) {
+    fprintf(stderr, "Couldn't connect to the X11 server.\n");
     return 1;
   }
 
-  auto dummmy_window = XCreateSimpleWindow(
-      xdisplay, root_window, 0 /*x*/, 0 /*y*/, 1 /*width*/, 1 /*height*/,
-      0 /*border width*/, 0 /*border*/, 0 /*background*/);
-  if (!dummmy_window) {
+  auto dummy_window = connection.GenerateId<x11::Window>();
+  auto req = connection.CreateWindow({
+      .wid = dummy_window,
+      .parent = connection.default_root(),
+      .width = 1,
+      .height = 1,
+      // We are only interested in the ReparentNotify events that are sent
+      // whenever our dummy window is reparented because of a wm start.
+      .event_mask = x11::EventMask::StructureNotify,
+  });
+  if (req.Sync().error) {
     fprintf(stderr, "Couldn't create a dummy window.");
     return 1;
   }
 
-  XMapWindow(xdisplay, dummmy_window);
-  // We are only interested in the ReparentNotify events that are sent whenever
-  // our dummy window is reparented because of a wm start.
-  XSelectInput(xdisplay, dummmy_window, StructureNotifyMask);
-  XFlush(xdisplay);
+  connection.MapWindow({dummy_window});
+  connection.Flush();
 
-  int display_fd = ConnectionNumber(xdisplay);
+  int display_fd = ConnectionNumber(connection.display());
 
   // Set deadline as 30s.
   struct timespec now, deadline;
@@ -82,7 +69,6 @@ int main(int argc, char* argv[]) {
   struct timeval tv;
   CalculateTimeout(now, deadline, &tv);
 
-  XEvent ev;
   do {
     fd_set in_fds;
     FD_ZERO(&in_fds);
@@ -95,14 +81,14 @@ int main(int argc, char* argv[]) {
         break;
       }
     } else if (ret > 0) {
-      while (XPending(xdisplay)) {
-        XNextEvent(xdisplay, &ev);
+      connection.ReadResponses();
+      for (const auto& event : connection.events()) {
         // If we got ReparentNotify, a wm has started up and we can stop
         // execution.
-        if (ev.type == ReparentNotify) {
+        if (event.As<x11::ReparentNotifyEvent>())
           return 0;
-        }
       }
+      connection.events().clear();
     }
     // Calculate next timeout. If it's less or equal to 0, give up.
     clock_gettime(CLOCK_REALTIME, &now);
@@ -114,7 +100,7 @@ int main(int argc, char* argv[]) {
 
 #if defined(LEAK_SANITIZER)
 // XOpenDisplay leaks memory if it takes more than one try to connect. This
-// causes LSan bots to fail. We don't care about memory leaks in xdisplaycheck
+// causes LSan bots to fail. We don't care about memory leaks in xwmstartupcheck
 // anyway, so just disable LSan completely.
 // This function isn't referenced from the executable itself. Make sure it isn't
 // stripped by the linker.