[sync::cleanup] Remove old EnumSet iter interface

https://chromium-review.googlesource.com/c/chromium/src/+/1145066 adds a
new STL-compatible interface to EnumSet and EnumSet::Iterator.

https://chromium-review.googlesource.com/c/chromium/src/+/1145182 and
https://chromium-review.googlesource.com/c/chromium/src/+/1145186 completely
remove usage of the old one.

Due to this, the old interface is not needed anymore.

This refers to the methods EnumSet::First (superseded by EnumSet::begin),
EnumSet::Iterator::Get (superseded by unary operator * for dereferencing) and
EnumSet::Iterator::Inc (superseded by unary operator ++ for incrementing).
Therefore, remove them. EnumSet::Iterator::Good remains because it is used
internally, but its visibility has been changed from public to private to
reflect this.

Bug: 860435
Change-Id: I7d27123cea02701795b6b9d278a3d9556fefc697
Reviewed-on: https://chromium-review.googlesource.com/1146929
Commit-Queue: David Davidović <davidovic@google.com>
Reviewed-by: vitaliii <vitaliii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584019}

components/sync/base/enum_set.h

@@ -84,26 +84,6 @@ class EnumSet {
     Iterator() : enums_(nullptr), i_(kValueCount) {}
     ~Iterator() {}
 
-    // Copy constructor and assignment welcome.
-
-    // Returns true iff the iterator points to an EnumSet and it
-    // hasn't yet traversed the EnumSet entirely.
-    bool Good() const { return enums_ && i_ < kValueCount && enums_->test(i_); }
-
-    // Returns the value the iterator currently points to.  Good()
-    // must hold.
-    E Get() const {
-      DCHECK(Good());
-      return FromIndex(i_);
-    }
-
-    // Moves the iterator to the next value in the EnumSet. Good()
-    // must hold. Takes linear time.
-    void Inc() {
-      DCHECK(Good());
-      i_ = FindNext(i_ + 1);
-    }
-
     bool operator==(const Iterator& other) const { return i_ == other.i_; }
 
     bool operator!=(const Iterator& other) const { return !(*this == other); }
@@ -134,12 +114,15 @@ class EnumSet {
     }
 
    private:
-    friend Iterator EnumSet::First() const;
     friend Iterator EnumSet::begin() const;
 
     explicit Iterator(const EnumBitSet& enums)
         : enums_(&enums), i_(FindNext(0)) {}
 
+    // Returns true iff the iterator points to an EnumSet and it
+    // hasn't yet traversed the EnumSet entirely.
+    bool Good() const { return enums_ && i_ < kValueCount && enums_->test(i_); }
+
     size_t FindNext(size_t i) {
       while ((i < kValueCount) && !enums_->test(i)) {
         ++i;
@@ -241,8 +224,6 @@ class EnumSet {
   size_t Size() const { return enums_.count(); }
 
   // Returns an iterator pointing to the first element (if any).
-  Iterator First() const { return Iterator(enums_); }
-
   Iterator begin() const { return Iterator(enums_); }
 
   // Returns an iterator that does not point to any element, but to the position

components/sync/base/enum_set_unittest.cc

@@ -197,8 +197,8 @@ TEST_F(EnumSetTest, HasAll) {
 TEST_F(EnumSetTest, Iterators) {
   const TestEnumSet enums1(TEST_3, TEST_4);
   TestEnumSet enums2;
-  for (TestEnumSet::Iterator it = enums1.First(); it.Good(); it.Inc()) {
-    enums2.Put(it.Get());
+  for (TestEnumSet::Iterator it = enums1.begin(); it != enums1.end(); it++) {
+    enums2.Put(*it);
   }
   EXPECT_EQ(enums2, enums1);
 }