Use AutofillProfileComparator in place of ad-hoc merge logic.

components/autofill/core/browser/phone_number.cc

Index: components/autofill/core/browser/phone_number.cc
diff --git a/components/autofill/core/browser/phone_number.cc b/components/autofill/core/browser/phone_number.cc
index 59f5e71834b2b3ecd30c4b460331751b5013fd3e..7dde9375f36febeee645ac3d71eca4133c35ea40 100644
--- a/components/autofill/core/browser/phone_number.cc
+++ b/components/autofill/core/browser/phone_number.cc
@@ -52,6 +52,13 @@ PhoneNumber& PhoneNumber::operator=(const PhoneNumber& number) {
   return *this;
 }
 
+bool PhoneNumber::operator==(const PhoneNumber& other) const {
+  if (this == &other)
+    return true;
+
+  return number_ == other.number_ && profile_ == other.profile_;

[sebsg, 2016/06/29 08:57:04]

I think profile_ == other.profiles_ results in a comparison of profiles
pointers?

If we use the object instead, the whole profile including it's guid and all of
it's content will be compared, which seems to be a lot more that what I would
expect from comparing phone numbers.

Since the only way profile_ is used in this class is to GetRegion(...), let's
add a TODO to check whether we could just keep the region instead of a pointer
to the profile.

In the meantime maybe we could check that 
GetRegion(*profile_, app_locale) == GetRegion(*(other.profile_), app_locale) or
something like that?

What do you think?

[Roger McFarlane (Chromium), 2016/06/29 18:21:37]

Hmmm...no, I don't think that's what we want.

We really just want to know if this phone number is the same as the other, so
that we know whether or not there really was a change. The profile is actually
somewhat inconsequential because the way the phone number is constructed when
this operator is used ensures that the phone_number being compared points to the
same profile.

We're might be better off just dropping the profile from the comparison, but the
assignment operators take care to handle it so I included it here as well.
The region and the phone number are not necessarily related. If the phone number
is international, it could refer to any region.
Alas, we don't have app_locale_ here.

I'm comfortable just doing the pointer comparison here since it's actually a
more-restrictive subset of the instances where operator== should return true
(i.e., it can never do the wrong thing), whereas, I think we need to think a bit
more about what it should return if the profiles are different.

+}
+
 void PhoneNumber::GetSupportedTypes(ServerFieldTypeSet* supported_types) const {
   supported_types->insert(PHONE_HOME_WHOLE_NUMBER);
   supported_types->insert(PHONE_HOME_NUMBER);