SkCanvas::clear() should call down to devices even when the clip is empty.

tests/CanvasTest.cpp

Index: tests/CanvasTest.cpp
diff --git a/tests/CanvasTest.cpp b/tests/CanvasTest.cpp
index 5437d5b2da96a0463041574b8772c664468a275c..58be9dadb2cfa1f8f5bf8cbf992dd05d39656d79 100644
--- a/tests/CanvasTest.cpp
+++ b/tests/CanvasTest.cpp
@@ -795,3 +795,17 @@ DEF_TEST(Canvas, reporter) {
 
     test_newraster(reporter);
 }
+
+// Make sure SkCanvas passes clear() calls down to its devices even when they're clipped out.
+DEF_TEST(Canvas_clear, reporter) {
+    SkBitmap bm;
+    bm.allocN32Pixels(1,1);
+
+    SkCanvas canvas(bm);
+    canvas.clear(SK_ColorRED);
+    REPORTER_ASSERT(reporter, SK_ColorRED == bm.getColor(0,0));
+
+    canvas.clipRect(SkRect::MakeEmpty());
+    canvas.clear(SK_ColorGREEN);
+    REPORTER_ASSERT(reporter, SK_ColorGREEN == bm.getColor(0,0));
+}