Auto merge of #22856 - jdm:angle, r=paulrouget

Add optional ANGLE support to glutin port

Supporting ANGLE in Servo has two important benefits:
* we can actually run Servo instances on our Windows CI machines, which gives us more confidence that we're not breaking it
* we can continue to use OpenGL on devices like the Hololens, rather than creating platform-specific graphical backends

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python/servo/build_commands.py

@@ -625,16 +625,23 @@ class MachCommands(CommandBase):
                                 servo_exe_dir)
                 # Search for the generated nspr4.dll
                 build_path = path.join(servo_exe_dir, "build")
-                nspr4 = "nspr4.dll"
-                nspr4_path = None
-                for root, dirs, files in os.walk(build_path):
-                    if nspr4 in files:
-                        nspr4_path = path.join(root, nspr4)
-                        break
-                if nspr4_path is None:
-                    print("WARNING: could not find nspr4.dll")
-                else:
-                    shutil.copy(nspr4_path, servo_exe_dir)
+
+                def package_generated_shared_libraries(libs, build_path, servo_exe_dir):
+                    for root, dirs, files in os.walk(build_path):
+                        remaining_libs = list(libs)
+                        for lib in libs:
+                            if lib in files:
+                                shutil.copy(path.join(root, lib), servo_exe_dir)
+                                remaining_libs.remove(lib)
+                                continue
+                        libs = remaining_libs
+                        if not libs:
+                            return
+                    for lib in libs:
+                        print("WARNING: could not find " + lib)
+
+                package_generated_shared_libraries(["nspr4.dll", "libEGL.dll"], build_path, servo_exe_dir)
+
                 # copy needed gstreamer DLLs in to servo.exe dir
                 gst_x64 = "X86_64" if msvc_x64 == "64" else "X86"
                 gst_root = ""

python/servo/testing_commands.py

@@ -971,3 +971,13 @@ testing/web-platform/mozilla/tests for Servo-only tests""" % reference_path)
         run_globals = {"__file__": run_file}
         execfile(run_file, run_globals)
         return run_globals["update_conformance"](version, dest_folder, None, patches_dir)
+
+    @Command('smoketest',
+             description='Load a simple page in Servo and ensure that it closes properly',
+             category='testing')
+    @CommandArgument('params', nargs='...',
+                     help="Command-line arguments to be passed through to Servo")
+    def smoketest(self, params):
+        params = params + ['tests/html/close-on-load.html']
+        return self.context.commands.dispatch(
+            'run', self.context, params=params)