Move GetFallbackIconText to favicon/core

Review URL: https://codereview.chromium.org/1427843007

Cr-Commit-Position: refs/heads/master@{#359849}
diff --git a/components/favicon.gypi b/components/favicon.gypi
index 71990a82..5d22e82 100644
--- a/components/favicon.gypi
+++ b/components/favicon.gypi
@@ -10,6 +10,7 @@
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
+        '../base/base.gyp:base_i18n',
         '../skia/skia.gyp:skia',
         '../ui/base/ui_base.gyp:ui_base',
         '../ui/gfx/gfx.gyp:gfx',
@@ -21,6 +22,8 @@
       ],
       'sources': [
         # Note: sources list duplicated in GN build.
+        'favicon/core/fallback_url_util.cc',
+        'favicon/core/fallback_url_util.h',
         'favicon/core/favicon_client.h',
         'favicon/core/favicon_driver.cc',
         'favicon/core/favicon_driver.h',