remove (this: any) casts from the codebase

Summary:
it's silly to hide errors by just casting to `any` and forgetting about it.
replace them with suppressions.

Reviewed By: pieterv

Differential Revision: D37478365

fbshipit-source-id: 5ea56890fba9fa78e9b47a8b7e868c7e8d862b1a

src/model/immutable/ContentState.js

@@ -79,15 +79,18 @@ class ContentState extends ContentStateRecord {
   }
 
   getBlockMap(): BlockMap {
-    return (this: any).get('blockMap');
+    // $FlowFixMe[prop-missing] found when removing casts of this to any
+    return this.get('blockMap');
   }
 
   getSelectionBefore(): SelectionState {
-    return (this: any).get('selectionBefore');
+    // $FlowFixMe[prop-missing] found when removing casts of this to any
+    return this.get('selectionBefore');
   }
 
   getSelectionAfter(): SelectionState {
-    return (this: any).get('selectionAfter');
+    // $FlowFixMe[prop-missing] found when removing casts of this to any
+    return this.get('selectionAfter');
   }
 
   getBlockForKey(key: string): BlockNodeRecord {
@@ -227,15 +230,18 @@ class ContentState extends ContentStateRecord {
   }
 
   setSelectionBefore(selection: SelectionState): ContentState {
-    return (this: any).set('selectionBefore', selection);
+    // $FlowFixMe[prop-missing] found when removing casts of this to any
+    return this.set('selectionBefore', selection);
   }
 
   setSelectionAfter(selection: SelectionState): ContentState {
-    return (this: any).set('selectionAfter', selection);
+    // $FlowFixMe[prop-missing] found when removing casts of this to any
+    return this.set('selectionAfter', selection);
   }
 
   setBlockMap(blockMap: BlockMap): ContentState {
-    return (this: any).set('blockMap', blockMap);
+    // $FlowFixMe[prop-missing] found when removing casts of this to any
+    return this.set('blockMap', blockMap);
   }
 
   static createFromBlockArray(