Bug 278091 [CSS] Measure.getCssText() with float value results in IllegalStateException
In theory we should be able to provide percentages as part of the gradients, e.g. CTabFolder:selected { background-color: #FF0000 #0000FF 30% } But this generates IllegalStateException calling getCSSText() on org.apache.batik.css.parser.CSSLexicalUnit$FloatLexicalUnit from Measure.getCSSText().
tests/org.eclipse.e4.ui.tests.css.swt/src/org/eclipse/e4/ui/tests/css/swt/GradientTest.java
CTabFolder folderToTest = createTestCTabFolder(
				"CTabFolder:selected { background-color: red green blue yellow 10%}");
		assertEquals(new int[] {33, 67, 100}, getSelectionGradientPercents(folderToTest)); 
	}
	/* 
	 * Test to ensure that one bad apple doesn't spoil it for everyone
	 * (non-existent color name is ignored)
	 */
	public void testBadColors() throws Exception {
		CTabFolder folderToTest = createTestCTabFolder(
				"CTabFolder:selected { background-color: #FF0000 notAColor #0000FF}");
		assertEquals(RED, getSelectionBackgroundBegin(folderToTest).getRGB()); 		
		assertEquals(BLUE, folderToTest.getSelectionBackground().getRGB()); 
		assertEquals(new int[] {100}, getSelectionGradientPercents(folderToTest)); 
	}
	
	/* 
	 * Test to ensure that a percent > 100 triggers default
	 */
	public void testAboveRangePercents() throws Exception {
		CTabFolder folderToTest = createTestCTabFolder(
				"CTabFolder:selected { background-color: #FF0000 #00FF00 #0000FF 20% 110%}");
		assertEquals(RED, getSelectionBackgroundBegin(folderToTest).getRGB()); 		
		assertEquals(BLUE, folderToTest.getSelectionBackground().getRGB()); 
		assertEquals(new int[] {50, 100}, getSelectionGradientPercents(folderToTest)); 
	}
	/* 
	 * Test to ensure that a percent < 0 triggers default
	 */
	public void testBelowRangePercents() throws Exception {