Add handling for Skia's SkPath::intersect's return value

content/shell/renderer/test_runner/mock_web_theme_engine.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/shell/renderer/test_runner/mock_web_theme_engine.h"
 
 #if !defined(OS_MACOSX)
 
 #include "base/logging.h"
 #include "skia/ext/platform_canvas.h"
@@ skipping 610 matching lines @@
         SkIRect tofill = irect;
         if (extraParams->progressBar.determinate) {
             tofill.set(extraParams->progressBar.valueRectX,
                 extraParams->progressBar.valueRectY,
                 extraParams->progressBar.valueRectX +
                 extraParams->progressBar.valueRectWidth - 1,
                 extraParams->progressBar.valueRectY +
                 extraParams->progressBar.valueRectHeight);
         }
 
-        tofill.intersect(irect, tofill);
+        if (!tofill.intersect(irect)) {
+            tofill.setEmpty();
+        }
         paint.setColor(edgeColor);
         paint.setStyle(SkPaint::kFill_Style);
         canvas->drawIRect(tofill, paint);
 
         markState(canvas, irect, state);
         break;
     }
     default:
         // FIXME: Should we do something here to indicate that we got an invalid part?
         // Unfortunately, we can't assert because we don't have access to WTF or base.
         break;
     }
 }
 
 }  // namespace content
 
 #endif  // !defined(OS_MACOSX)