Allow 0-width SkBitmap in setConfig.

tests/BitmapTest.cpp

+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkBitmap.h"
+
+#include "Test.h"
+#include "TestClassDef.h"
+
+/**
+ *  This test contains basic sanity checks concerning bitmaps.
+ */
+DEF_TEST(Bitmap, reporter) {
+    const SkBitmap::Config conf = SkBitmap::kARGB_8888_Config;
+    // Zero-sized bitmaps are allowed
+    for (int width = 0; width < 2; ++width) {
+        for (int height = 0; height < 2; ++height) {
+            SkBitmap bm;
+            bool setConf = bm.setConfig(conf, width, height);
+            REPORTER_ASSERT(reporter, setConf);
+            if (setConf) {
+                REPORTER_ASSERT(reporter, bm.allocPixels(NULL));
+            }
+            REPORTER_ASSERT(reporter, (width & height) != bm.empty());
+        }
+    }
+}