Add path option(path2d) for hit regions on canvas2d.

Source/core/html/canvas/CanvasRenderingContext2D.cpp

Index: Source/core/html/canvas/CanvasRenderingContext2D.cpp
diff --git a/Source/core/html/canvas/CanvasRenderingContext2D.cpp b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
index 106c93fae5d436049d583a4aae50282c7165b75e..b91681c998d2fa85dd0f37079a14caf2af10ab1f 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.cpp
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
@@ -2373,16 +2373,24 @@ void CanvasRenderingContext2D::addHitRegion(const Dictionary& options, Exception
         return;
     }
 
+    RefPtr<Path2D> path2d;
+    options.getWithUndefinedOrNullCheck("path", path2d);
+
+    Path specifiedPath;
+    if (path2d)
+        specifiedPath = path2d->path();
+    else
+        specifiedPath = m_path;

[Rik, 2014/06/29 03:22:22]

Will the current CTM be applied to the path that you pass in?

[zino, 2014/06/29 04:07:18]

Yes, you can see here.
2394     specifiedPath.transform(state().m_transform);

+
     FloatRect clipBounds;
     GraphicsContext* context = drawingContext();
 
-    if (m_path.isEmpty() || !context || !state().m_invertibleCTM
+    if (specifiedPath.isEmpty() || !context || !state().m_invertibleCTM
         || !context->getTransformedClipBounds(&clipBounds)) {
         exceptionState.throwDOMException(NotSupportedError, "The specified path has no pixels.");
         return;
     }
 
-    Path specifiedPath = m_path;
     specifiedPath.transform(state().m_transform);
 
     if (context->isClipMode()) {