Bug 535962 - Submit button cut off

Set heightHint for submit button on GTK to prevent cutoff.

Change-Id: I0b697a9648220edff4c37d34c6366d02032898b5
Signed-off-by: Xi Yan <xixiyan@redhat.com>
diff --git a/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/ToolBarButtonContribution.java b/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/ToolBarButtonContribution.java
index db706f0..2719c0f 100644
--- a/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/ToolBarButtonContribution.java
+++ b/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/ToolBarButtonContribution.java
@@ -54,6 +54,8 @@
 			heigtHint = 22;
 		} else if (Platform.WS_CARBON.equals(SWT.getPlatform())) {
 			heigtHint = 32;
+		} else if (Platform.WS_GTK.equals(SWT.getPlatform())) {
+			heigtHint = 26;
 		}
 		GridDataFactory.fillDefaults().align(SWT.BEGINNING, SWT.CENTER).hint(SWT.DEFAULT, heigtHint).applyTo(button);
 		return composite;