Avoid passing uninitialized value to markRectAsNonOpaque.

Source/platform/graphics/GraphicsContextTest.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
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  * 1.  Redistributions of source code must retain the above copyright
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  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 1024 matching lines @@
     context.setFillColor(opaque);
     path.moveTo(FloatPoint(10, 10));
     path.addLineTo(FloatPoint(40, 40));
     context.strokePath(path);
 
     context.endLayer();
     EXPECT_EQ_RECT(IntRect(), context.opaqueRegion().asRect());
     EXPECT_PIXELS_MATCH_EXACT(bitmap, context.opaqueRegion().asRect());
 }
 
+TEST(GraphicsContextTest, OpaqueRegionForLayer)
+{
+    SkBitmap bitmap;

[danakj, 2014/07/30 13:31:25]

What makes the device clip not a Rect in this test?

[sohanjg, 2014/07/30 13:41:54]

This is still a Rect, i wonder how can we set device clip as non rect ?
This test will only cover markRectAsNonOpaque(deviceClipRect) code, and not the
markAllAsNonOpaque() code.

[sohanjg, 2014/07/31 15:44:34]

Done.

+    ASSERT_TRUE(bitmap.allocN32Pixels(100, 100));
+    bitmap.eraseColor(0);
+    SkCanvas canvas(bitmap);
+
+    GraphicsContext context(&canvas);
+    context.setTrackOpaqueRegion(true);
+
+    Path path;
+    Color opaque(1.0f, 0.0f, 0.0f, 1.0f);
+
+    // Set Opaque Rect.
+    context.fillRect(FloatRect(30, 30, 90, 90), opaque, CompositeSourceOver);
+    // Begin non-opaque-preserving layer.
+    context.setCompositeOperation(CompositeSourceOut);
+    context.beginTransparencyLayer(0.5);
+
+    context.endLayer();
+    EXPECT_EQ_RECT(IntRect(), context.opaqueRegion().asRect());
+    EXPECT_PIXELS_MATCH_EXACT(bitmap, context.opaqueRegion().asRect());
+
+    // Set Opaque Rect.
+    context.fillRect(FloatRect(30, 30, 90, 90), opaque, CompositeSourceOver);
+    // Begin opaque-preserving layer.
+    context.setCompositeOperation(CompositeSourceOver);
+    context.beginTransparencyLayer(0.5);
+
+    context.endLayer();
+    EXPECT_EQ_RECT(IntRect(30, 30, 70, 70), context.opaqueRegion().asRect());
+    EXPECT_PIXELS_MATCH(bitmap, context.opaqueRegion().asRect());
+}
+
 #define DISPATCH1(c1, c2, op, param1) do { c1.op(param1); c2.op(param1); } while (0);
 #define DISPATCH2(c1, c2, op, param1, param2) do { c1.op(param1, param2); c2.op(param1, param2); } while (0);
 
 TEST(GraphicsContextTest, RecordingTotalMatrix)
 {
     SkBitmap bitmap;
     ASSERT_TRUE(bitmap.allocN32Pixels(400, 400));
     bitmap.eraseColor(0);
     SkCanvas canvas(bitmap);
     GraphicsContext context(&canvas);
@@ skipping 59 matching lines @@
     EXPECT_FALSE(pic);
 
     // endRecording finally makes the picture accessible
     dl->endRecording();
     pic = dl->picture();
     EXPECT_TRUE(pic);
     EXPECT_EQ(1, pic->getRefCnt());
 }
 
 } // namespace