Bug 1062071 - Mark TileInternal's constructor as explicit; r=mattwoodrow

gfx/2d/DrawTargetTiled.cpp

@@ -27,7 +27,7 @@ DrawTargetTiled::Init(const TileSet& aTiles)
 
   mTiles.reserve(aTiles.mTileCount);
   for (size_t i = 0; i < aTiles.mTileCount; ++i) {
-    mTiles.push_back(aTiles.mTiles[i]);
+    mTiles.push_back(TileInternal(aTiles.mTiles[i]));
     if (!aTiles.mTiles[i].mDrawTarget) {
       return false;
     }

gfx/2d/DrawTargetTiled.h

@@ -19,7 +19,7 @@ struct TileInternal : public Tile {
     : mClippedOut(false)
   {}
 
-  TileInternal(const Tile& aOther)
+  explicit TileInternal(const Tile& aOther)
     : Tile(aOther)
     , mClippedOut(false)
   {}