[Autofill] Make PersonalDataManager::OverwriteWith case sensitive.

components/autofill/core/browser/autofill_profile.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_AUTOFILL_CORE_BROWSER_AUTOFILL_PROFILE_H_
 #define COMPONENTS_AUTOFILL_CORE_BROWSER_AUTOFILL_PROFILE_H_
 
 #include <stddef.h>
 
 #include <iosfwd>
@@ skipping 96 matching lines @@
   // Returns true if the data in this AutofillProfile is a subset of the data in
   // |profile|.
   bool IsSubsetOf(const AutofillProfile& profile,
                   const std::string& app_locale) const;
 
   // Like IsSubsetOf, but only considers the types present in |types|.
   bool IsSubsetOfForFieldSet(const AutofillProfile& profile,
                              const std::string& app_locale,
                              const ServerFieldTypeSet& types) const;
 
-  // Overwrites the field data in |profile| with this Profile. Returns |true| if
-  // at least one field was overwritten.
+  // Overwrites the field data in this Profile with the non-empty fields in
+  // |profile|. Returns |true| if at least one field was overwritten.
+  // The usage stats, the origin and the language code are always updated and
+  // have no effect on the return value.
   bool OverwriteWith(const AutofillProfile& profile,
                      const std::string& app_locale);
 
   // Saves info from |profile| into |this|, provided |this| and |profile| do not
   // have any direct conflicts (i.e. data is present but different). Will not
   // make changes if |this| is verified and |profile| is not. Returns true if
   // |this| and |profile| are similar.
   bool SaveAdditionalInfo(const AutofillProfile& profile,
                           const std::string& app_locale);
 
@@ skipping 118 matching lines @@
   // a hash of the contents.
   std::string server_id_;
 };
 
 // So we can compare AutofillProfiles with EXPECT_EQ().
 std::ostream& operator<<(std::ostream& os, const AutofillProfile& profile);
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_CORE_BROWSER_AUTOFILL_PROFILE_H_