Add fields for recording property getters and setters.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=188532250

src/com/google/javascript/jscomp/AbstractCompiler.java

@@ -564,6 +564,75 @@ abstract void updateGlobalVarReferences(Map<Var, ReferenceCollection>
 
   abstract void addComments(String filename, List<Comment> comments);
 
+  /** Indicates whether a property has a getter or a setter, or both. */
+  public enum PropertyAccessKind {
+    // To save space properties without getters or setters won't appear
+    // in the maps at all, but NORMAL will be returned by some methods.
+    NORMAL(0),
+    GETTER_ONLY(1),
+    SETTER_ONLY(2),
+    GETTER_AND_SETTER(3);
+
+    final byte flags;
+
+    PropertyAccessKind(int flags) {
+      this.flags = (byte) flags;
+    }
+
+    boolean hasGetter() {
+      return (flags & 1) != 0;
+    }
+
+    boolean hasSetter() {
+      return (flags & 2) != 0;
+    }
+
+    boolean hasGetterOrSetter() {
+      return (flags & 3) != 0;
+    }
+
+    // used to combine information from externs and from sources
+    PropertyAccessKind unionWith(PropertyAccessKind other) {
+      int combinedFlags = this.flags | other.flags;
+      switch (combinedFlags) {
+        case 0:
+          return NORMAL;
+        case 1:
+          return GETTER_ONLY;
+        case 2:
+          return SETTER_ONLY;
+        case 3:
+          return GETTER_AND_SETTER;
+        default:
+          throw new IllegalStateException("unexpected value: " + combinedFlags);
+      }
+    }
+  }
+
+  /**
+   * Returns a map containing an entry for every property name found in the externs files with
+   * a getter and / or setter defined.
+   *
+   * <p>Property names for which there are no getters or setters will not be in the map.
+   */
+  abstract ImmutableMap<String, PropertyAccessKind> getExternGetterAndSetterProperties();
+
+  /** Sets the map of extern properties with getters and setters. */
+  abstract void setExternGetterAndSetterProperties(
+      ImmutableMap<String, PropertyAccessKind> externGetterAndSetterProperties);
+
+  /**
+   * Returns a map containing an entry for every property name found in the source AST with
+   * a getter and / or setter defined.
+   *
+   * <p>Property names for which there are no getters or setters will not be in the map.
+   */
+  abstract ImmutableMap<String, PropertyAccessKind> getSourceGetterAndSetterProperties();
+
+  /** Sets the map of properties with getters and setters defined in the sources AST. */
+  abstract void setSourceGetterAndSetterProperties(
+      ImmutableMap<String, PropertyAccessKind> externGetterAndSetterProperties);
+
   /**
    * Returns all the comments from the given file.
    */

src/com/google/javascript/jscomp/Compiler.java

@@ -269,6 +269,8 @@ public SourceFile loadSource(String filename) {
   private String lastPassName;
 
   private Set<String> externProperties = null;
+  private ImmutableMap<String, PropertyAccessKind> externGetterAndSetterProperties = null;
+  private ImmutableMap<String, PropertyAccessKind> sourceGetterAndSetterProperties = null;
 
   private static final Joiner pathJoiner = Joiner.on(File.separator);
 
@@ -3268,6 +3270,28 @@ Set<String> getExternProperties() {
     return externProperties;
   }
 
+  @Override
+  ImmutableMap<String, PropertyAccessKind> getExternGetterAndSetterProperties() {
+    return externGetterAndSetterProperties;
+  }
+
+  @Override
+  void setExternGetterAndSetterProperties(
+      ImmutableMap<String, PropertyAccessKind> externGetterAndSetterProperties) {
+    this.externGetterAndSetterProperties = externGetterAndSetterProperties;
+  }
+
+  @Override
+  ImmutableMap<String, PropertyAccessKind> getSourceGetterAndSetterProperties() {
+    return sourceGetterAndSetterProperties;
+  }
+
+  @Override
+  void setSourceGetterAndSetterProperties(
+      ImmutableMap<String, PropertyAccessKind> sourceGetterAndSetterProperties) {
+    this.sourceGetterAndSetterProperties = sourceGetterAndSetterProperties;
+  }
+
   /**
    * Replaces one file in a hot-swap mode. The given JsAst should be made
    * from a new version of a file that already was present in the last compile