Bug 703028: Fix obnoxious warning spew from gfx 2d stuff. r=me

gfx/2d/Point.h

@@ -59,7 +59,7 @@ struct Point :
 
   Point() : Super() {}
   Point(Float aX, Float aY) : Super(aX, aY) {}
-  Point(const IntPoint& point) : Super(point.x, point.y) {}
+  Point(const IntPoint& point) : Super(float(point.x), float(point.y)) {}
 };
 
 struct IntSize :
@@ -76,7 +76,8 @@ struct Size :
 
   Size() : Super() {}
   Size(Float aWidth, Float aHeight) : Super(aWidth, aHeight) {}
-  explicit Size(const IntSize& size) : Super(size.width, size.height) {}
+  explicit Size(const IntSize& size) :
+    Super(float(size.width), float(size.height)) {}
 };
 
 }

gfx/2d/Rect.h

@@ -81,7 +81,8 @@ struct Rect :
     Rect(Float _x, Float _y, Float _width, Float _height) :
         Super(_x, _y, _width, _height) {}
     explicit Rect(const IntRect& rect) :
-        Super(rect.x, rect.y, rect.width, rect.height) {}
+        Super(float(rect.x), float(rect.y),
+              float(rect.width), float(rect.height)) {}
 };
 
 }