Don't let PaintInvalidationLocationChange shadow other reasons

third_party/WebKit/LayoutTests/platform/win/media/video-paint-invalidation-expected.txt

 {
   "bounds": [800, 600],
   "children": [
     {
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "children": [
         {
           "position": [8, 8],
@@ skipping 28 matching lines @@
                   "reason": "full"
                 },
                 {
                   "object": "LayoutButton INPUT",
                   "rect": [193, 205, 36, 30],
                   "reason": "full"
                 },
                 {
                   "object": "LayoutBlockFlow DIV id='thumb'",
                   "rect": [118, 208, 33, 24],
-                  "reason": "location change"
+                  "reason": "full"
                 },
                 {
                   "object": "LayoutBlockFlow DIV id='thumb'",
                   "rect": [47, 208, 32, 24],
-                  "reason": "location change"
+                  "reason": "full"
                 },
                 {
                   "object": "LayoutButton INPUT",
                   "rect": [14, 205, 30, 30],
                   "reason": "full"
                 },
                 {
                   "object": "LayoutBlockFlow (anonymous)",
                   "rect": [159, 205, 26, 23],
                   "reason": "invalidate paint rectangle"
@@ skipping 17 matching lines @@
                 }
               ]
             }
           ]
         }
       ]
     }
   ]
 }