Fix the CubeSea WebXR test page, which uses a removed API

The page uses viewport scaling, which was removed.

Change-Id: I40c6c2c65bcf6fa1a3c831a339bfdd2071bd7084
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1656380Reviewed-by: Bill Orr <billorr@chromium.org>
Reviewed-by: Brian Sheedy <bsheedy@chromium.org>
Commit-Queue: Bill Orr <billorr@chromium.org>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Auto-Submit: Bill Orr <billorr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#668566}

third_party/webxr_test_pages/webxr-samples/tests/cube-sea.html

@@ -158,9 +158,6 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
         // Framebuffer scale override. 1 = default
         framebufferScale: getFloatParam('framebufferScale', 1),
 
-        // Viewport scale
-        viewportScale: getFloatParam('viewportScale', 1),
-
         // Immersive AR mode
         arMode: getBoolParam('arMode', false),
 
@@ -205,8 +202,6 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
       var folderRender = gui.addFolder('Rendering options');
       folderRender.add(appSettings, 'framebufferScale', 0, 2, 0.25).onFinishChange(
           getParamSaver('framebufferScale'));
-      folderRender.add(appSettings, 'viewportScale', 0.25, 1, 0.125).onFinishChange(
-          getParamSaver('viewportScale'));
       folderRender.add(appSettings, 'antialias').onFinishChange(
           getParamSaver('antialias'));
       folderRender.add(appSettings, 'arMode').onFinishChange(
@@ -381,8 +376,6 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
           }
         }
 
-        session.renderState.baseLayer.requestViewportScaling(appSettings.viewportScale);
-
         session.requestAnimationFrame(onXRFrame);
 
         // Simulate a poorly designed app that doesn't provide frames.