Replace nil -> NULL in the views code.

Review URL: http://codereview.appspot.com/67139


git-svn-id: http://skia.googlecode.com/svn/trunk@200 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/views/SkProgressBarView.cpp b/src/views/SkProgressBarView.cpp
index 21349a5..a9fd516 100644
--- a/src/views/SkProgressBarView.cpp
+++ b/src/views/SkProgressBarView.cpp
@@ -28,7 +28,7 @@
 	SkAnimator::DifferenceType	diff = fAnim.draw(canvas, &paint, SkTime::GetMSecs());
 	
 	if (diff == SkAnimator::kDifferent)
-		this->inval(nil);
+		this->inval(NULL);
 	else if (diff == SkAnimator::kPartiallyDifferent)
 	{
 		SkRect	bounds;
@@ -41,7 +41,7 @@
 {
 	if (evt.isType(SK_EventType_Inval))
 	{
-		this->inval(nil);
+		this->inval(NULL);
 		return true;
 	}
 	if (evt.isType("recommendDim"))