[WebXR] Implement clipping planes clamping

The WebXR specs specify[1] that user agents should enforce a minimum near clip plane and a maximum far clip plane. In particular they
must not be negative.

[1] https://immersive-web.github.io/webxr/#minimum-near-clip-plane

WPT test

Change-Id: Ib9c7dbbd524d24e657ea85f9bb9208bfc80a6aef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5185618
Commit-Queue: Sergio Villar <[email protected]>
Reviewed-by: Alexander Cooper <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1252767}

webxr/render_state_update.https.html

@@ -77,6 +77,40 @@
   });
 };
 
+let testMinMaxClippingPlanes = function(session, fakeDeviceController, t, sessionObjects) {
+  return new Promise((resolve, reject) => {
+    let gl = sessionObjects.gl;
+    gl.makeXRCompatible().then(() => {
+      t.step(() => {
+        let near = 0.2;
+        let far = 0.8;
+        let layer = new XRWebGLLayer(session, gl);
+        session.updateRenderState({ depthNear: near, depthFar: far, baseLayer: layer });
+        assert_not_equals(session.renderState.depthNear, near);
+        assert_not_equals(session.renderState.depthFar, far);
+        assert_not_equals(session.renderState.baseLayer, layer);
+        session.requestAnimationFrame((time, xrFrame) => {
+          t.step(() => {
+            assert_equals(session.renderState.depthNear, near);
+            assert_equals(session.renderState.depthFar, far);
+            // Clamp negative values
+            near = -20.3;
+            far = -1.5;
+            session.updateRenderState({ depthNear: near, depthFar: far });
+            session.requestAnimationFrame((time, xrFrame) => {
+              t.step(() => {
+                assert_equals(session.renderState.depthNear, 0.0);
+                assert_equals(session.renderState.depthFar, 0.0);
+                resolve();
+              });
+            });
+          });
+        });
+      });
+    });
+  });
+};
+
 let testName = "updateRenderState handles appropriately ended sessions";
 xr_session_promise_test(testName, testSessionEnded, fakeDeviceInitParams, 'immersive-vr');
 
@@ -92,4 +126,7 @@
 testName = "updateRenderState handles appropriately XRRenderStateInit params";
 xr_session_promise_test(testName, testParams, fakeDeviceInitParams, 'inline');
 
+testName = "updateRenderState clamps appropriately near/far clipping planes";
+xr_session_promise_test(testName, testMinMaxClippingPlanes, fakeDeviceInitParams, 'immersive-vr');
+
 </script>