Use System.lineSeparator()

Benefit of this way rather than System.getProperty("line.separator") is
that there are no security checks.

Change-Id: I93238e3264e84914a090439a785f343f206d4597
Signed-off-by: Lars Vogel <Lars.Vogel@vogella.com>
diff --git a/tests/org.eclipse.core.tests.harness/src/org/eclipse/core/tests/session/SessionTestRunner.java b/tests/org.eclipse.core.tests.harness/src/org/eclipse/core/tests/session/SessionTestRunner.java
index d7140d9..17dd459 100644
--- a/tests/org.eclipse.core.tests.harness/src/org/eclipse/core/tests/session/SessionTestRunner.java
+++ b/tests/org.eclipse.core.tests.harness/src/org/eclipse/core/tests/session/SessionTestRunner.java
@@ -172,7 +172,7 @@
 			if (stack != null) {
 				// build the stack trace line by line
 				stack.append(message);
-				stack.append(System.getProperty("line.separator"));
+				stack.append(System.lineSeparator());
 				return;
 			}
 		}
diff --git a/tests/org.eclipse.core.tests.runtime/src/org/eclipse/core/tests/runtime/perf/ContentTypePerformanceTest.java b/tests/org.eclipse.core.tests.runtime/src/org/eclipse/core/tests/runtime/perf/ContentTypePerformanceTest.java
index 60ebab9..e4575ea 100644
--- a/tests/org.eclipse.core.tests.runtime/src/org/eclipse/core/tests/runtime/perf/ContentTypePerformanceTest.java
+++ b/tests/org.eclipse.core.tests.runtime/src/org/eclipse/core/tests/runtime/perf/ContentTypePerformanceTest.java
@@ -53,7 +53,7 @@
 		String id = "performance" + number;
 		String definition = generateContentType(number, id, baseTypeId, new String[] {DEFAULT_NAME}, null);
 		writer.write(definition);
-		writer.write(System.getProperty("line.separator"));
+		writer.write(System.lineSeparator());
 		return id;
 	}
 
@@ -186,7 +186,7 @@
 			} catch (MalformedURLException e) {
 				fail(tag + ".0.5", e);
 			}
-			String eol = System.getProperty("line.separator");
+			String eol = System.lineSeparator();
 			try (Writer writer = new BufferedWriter(new FileWriter(pluginLocation.append("plugin.xml").toFile()),
 					0x10000)) {
 				writer.write("<plugin>");
diff --git a/tests/org.eclipse.e4.core.tests/src/org/eclipse/e4/core/internal/tests/about/AboutTest.java b/tests/org.eclipse.e4.core.tests/src/org/eclipse/e4/core/internal/tests/about/AboutTest.java
index 3c5b47a..672852a 100644
--- a/tests/org.eclipse.e4.core.tests/src/org/eclipse/e4/core/internal/tests/about/AboutTest.java
+++ b/tests/org.eclipse.e4.core.tests/src/org/eclipse/e4/core/internal/tests/about/AboutTest.java
@@ -98,7 +98,7 @@
 
 	@Test
 	public void testMultilineValue() throws Exception {
-		String lf = System.getProperty("line.separator");
+		String lf = System.lineSeparator();
 		String key = "A_MULTILINE_PROPERTY";
 		String value = "a" + "\n" + "b" + "\n" + "c";
 		String expected = "a" + lf + "b" + lf + "c";