Implement basic parts of hit regions on canvas2d.

LayoutTests/fast/canvas/canvas-hit-regions-clip-test-expected.txt

Index: LayoutTests/fast/canvas/canvas-hit-regions-clip-test-expected.txt
diff --git a/LayoutTests/fast/canvas/canvas-hit-regions-clip-test-expected.txt b/LayoutTests/fast/canvas/canvas-hit-regions-clip-test-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..e2bc0249b02ac7f5b4d74fea4995e73fc8905b17
--- /dev/null
+++ b/LayoutTests/fast/canvas/canvas-hit-regions-clip-test-expected.txt
@@ -0,0 +1,31 @@
+Simple rect clip tests.
+PASS clickCanvas(10, 10) is null
+PASS clickCanvas(60, 60) is 'clip'
+
+Non rect clip tests.
+PASS clickCanvas(0, 0) is null
+PASS clickCanvas(100, 0) is null
+PASS clickCanvas(100, 100) is null
+PASS clickCanvas(0, 100) is null
+PASS clickCanvas(50, 50) is 'clip'
+
+Multiple clip tests.
+PASS clickCanvas(0, 0) is null
+PASS clickCanvas(100, 0) is 'clip'
+PASS clickCanvas(100, 100) is null
+PASS clickCanvas(0, 100) is null
+PASS clickCanvas(50, 0) is null
+PASS clickCanvas(150, 0) is null
+PASS clickCanvas(150, 100) is null
+PASS clickCanvas(50, 100) is null
+PASS clickCanvas(50, 50) is 'clip'
+PASS clickCanvas(100, 50) is 'clip'
+
+No pixels tests.
+PASS context.addHitRegion({ id : 'clip' }) threw exception NotSupportedError: Failed to execute 'addHitRegion' on 'CanvasRenderingContext2D': The specified path has no pixels..
+PASS context.addHitRegion({ id : 'clip' }) threw exception NotSupportedError: Failed to execute 'addHitRegion' on 'CanvasRenderingContext2D': The specified path has no pixels..
+
+PASS successfullyParsed is true
+
+TEST COMPLETE
+