Fixed issue where CanvasRenderer setClearColor wasn't working as expected.

src/renderers/CanvasRenderer.js

@@ -103,6 +103,7 @@ THREE.CanvasRenderer = function ( parameters ) {
 		_canvas.height = _canvasHeight;
 
 		_clipRect.set( - _canvasWidthHalf, - _canvasHeightHalf, _canvasWidthHalf, _canvasHeightHalf );
+		_clearRect.set( - _canvasWidthHalf, - _canvasHeightHalf, _canvasWidthHalf, _canvasHeightHalf );
 
 		_contextGlobalAlpha = 1;
 		_contextGlobalCompositeOperation = 0;