diff --git a/java/res/drawable-hdpi/btn_keyboard_key_normal.9.png b/java/res/drawable-hdpi/btn_keyboard_key_normal.9.png
deleted file mode 100644
index 3e25180..0000000
--- a/java/res/drawable-hdpi/btn_keyboard_key_normal.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-hdpi/btn_keyboard_key_normal_off.9.png b/java/res/drawable-hdpi/btn_keyboard_key_normal_off.9.png
deleted file mode 100644
index bad360f..0000000
--- a/java/res/drawable-hdpi/btn_keyboard_key_normal_off.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-hdpi/btn_keyboard_key_normal_on.9.png b/java/res/drawable-hdpi/btn_keyboard_key_normal_on.9.png
deleted file mode 100644
index 49f5198..0000000
--- a/java/res/drawable-hdpi/btn_keyboard_key_normal_on.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-hdpi/btn_keyboard_key_pressed.9.png b/java/res/drawable-hdpi/btn_keyboard_key_pressed.9.png
deleted file mode 100644
index e784edd..0000000
--- a/java/res/drawable-hdpi/btn_keyboard_key_pressed.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-hdpi/btn_keyboard_key_pressed_off.9.png b/java/res/drawable-hdpi/btn_keyboard_key_pressed_off.9.png
deleted file mode 100644
index a4731cf..0000000
--- a/java/res/drawable-hdpi/btn_keyboard_key_pressed_off.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-hdpi/btn_keyboard_key_pressed_on.9.png b/java/res/drawable-hdpi/btn_keyboard_key_pressed_on.9.png
deleted file mode 100644
index 03e163c..0000000
--- a/java/res/drawable-hdpi/btn_keyboard_key_pressed_on.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-hdpi/ic_subtype_mic_dark.png b/java/res/drawable-hdpi/ic_subtype_mic_dark.png
deleted file mode 100644
index eacbcd2..0000000
--- a/java/res/drawable-hdpi/ic_subtype_mic_dark.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-mdpi/btn_keyboard_key_normal.9.png b/java/res/drawable-mdpi/btn_keyboard_key_normal.9.png
deleted file mode 100644
index 12bc979..0000000
--- a/java/res/drawable-mdpi/btn_keyboard_key_normal.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-mdpi/btn_keyboard_key_normal_off.9.png b/java/res/drawable-mdpi/btn_keyboard_key_normal_off.9.png
deleted file mode 100644
index 44bd414..0000000
--- a/java/res/drawable-mdpi/btn_keyboard_key_normal_off.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-mdpi/btn_keyboard_key_normal_on.9.png b/java/res/drawable-mdpi/btn_keyboard_key_normal_on.9.png
deleted file mode 100644
index 43fdf5b..0000000
--- a/java/res/drawable-mdpi/btn_keyboard_key_normal_on.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-mdpi/btn_keyboard_key_pressed.9.png b/java/res/drawable-mdpi/btn_keyboard_key_pressed.9.png
deleted file mode 100644
index 1c1f3d7..0000000
--- a/java/res/drawable-mdpi/btn_keyboard_key_pressed.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-mdpi/btn_keyboard_key_pressed_off.9.png b/java/res/drawable-mdpi/btn_keyboard_key_pressed_off.9.png
deleted file mode 100644
index dacb675..0000000
--- a/java/res/drawable-mdpi/btn_keyboard_key_pressed_off.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-mdpi/btn_keyboard_key_pressed_on.9.png b/java/res/drawable-mdpi/btn_keyboard_key_pressed_on.9.png
deleted file mode 100644
index 3daa69f..0000000
--- a/java/res/drawable-mdpi/btn_keyboard_key_pressed_on.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-mdpi/sym_keyboard_mic_holo_light.png b/java/res/drawable-mdpi/sym_keyboard_mic_holo_light.png
deleted file mode 100644
index 84a63dc..0000000
--- a/java/res/drawable-mdpi/sym_keyboard_mic_holo_light.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-xhdpi/btn_keyboard_key_normal.9.png b/java/res/drawable-xhdpi/btn_keyboard_key_normal.9.png
deleted file mode 100644
index 026005d..0000000
--- a/java/res/drawable-xhdpi/btn_keyboard_key_normal.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-xhdpi/btn_keyboard_key_normal_off.9.png b/java/res/drawable-xhdpi/btn_keyboard_key_normal_off.9.png
deleted file mode 100644
index 38c5f24..0000000
--- a/java/res/drawable-xhdpi/btn_keyboard_key_normal_off.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-xhdpi/btn_keyboard_key_normal_on.9.png b/java/res/drawable-xhdpi/btn_keyboard_key_normal_on.9.png
deleted file mode 100644
index f1223e5..0000000
--- a/java/res/drawable-xhdpi/btn_keyboard_key_normal_on.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-xhdpi/btn_keyboard_key_pressed.9.png b/java/res/drawable-xhdpi/btn_keyboard_key_pressed.9.png
deleted file mode 100644
index ec35db5..0000000
--- a/java/res/drawable-xhdpi/btn_keyboard_key_pressed.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-xhdpi/btn_keyboard_key_pressed_off.9.png b/java/res/drawable-xhdpi/btn_keyboard_key_pressed_off.9.png
deleted file mode 100644
index bd30464..0000000
--- a/java/res/drawable-xhdpi/btn_keyboard_key_pressed_off.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-xhdpi/btn_keyboard_key_pressed_on.9.png b/java/res/drawable-xhdpi/btn_keyboard_key_pressed_on.9.png
deleted file mode 100644
index a3ff5d1..0000000
--- a/java/res/drawable-xhdpi/btn_keyboard_key_pressed_on.9.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-xhdpi/ic_subtype_mic_dark.png b/java/res/drawable-xhdpi/ic_subtype_mic_dark.png
deleted file mode 100644
index 17581ba..0000000
--- a/java/res/drawable-xhdpi/ic_subtype_mic_dark.png
+++ /dev/null
Binary files differ
diff --git a/java/res/drawable-xxhdpi/ic_subtype_mic_dark.png b/java/res/drawable-xxhdpi/ic_subtype_mic_dark.png
deleted file mode 100644
index 811103a..0000000
--- a/java/res/drawable-xxhdpi/ic_subtype_mic_dark.png
+++ /dev/null
Binary files differ
diff --git a/java/res/values-h1200dp-port/setup-dimens-large-tablet-port.xml b/java/res/values-h1200dp-port/setup-dimens-large-tablet-port.xml
index bc7928d..adc3e35 100644
--- a/java/res/values-h1200dp-port/setup-dimens-large-tablet-port.xml
+++ b/java/res/values-h1200dp-port/setup-dimens-large-tablet-port.xml
@@ -20,7 +20,6 @@
     <dimen name="setup_welcome_description_text_size">38sp</dimen>
     <dimen name="setup_step_bullet_text_size">24sp</dimen>
     <dimen name="setup_step_triangle_indicator_height">24dp</dimen>
-    <dimen name="setup_step_indicator_height">24dp</dimen>
     <dimen name="setup_step_title_text_size">24sp</dimen>
     <dimen name="setup_step_instruction_text_size">18sp</dimen>
     <dimen name="setup_step_action_text_size">20sp</dimen>
diff --git a/java/res/values-h330dp-land/setup-dimens-large-phone-land.xml b/java/res/values-h330dp-land/setup-dimens-large-phone-land.xml
index aebf6d2..1ff43ff 100644
--- a/java/res/values-h330dp-land/setup-dimens-large-phone-land.xml
+++ b/java/res/values-h330dp-land/setup-dimens-large-phone-land.xml
@@ -20,7 +20,6 @@
     <dimen name="setup_welcome_description_text_size">22sp</dimen>
     <dimen name="setup_step_bullet_text_size">22sp</dimen>
     <dimen name="setup_step_triangle_indicator_height">24dp</dimen>
-    <dimen name="setup_step_indicator_height">24dp</dimen>
     <dimen name="setup_step_title_text_size">20sp</dimen>
     <dimen name="setup_step_instruction_text_size">16sp</dimen>
     <dimen name="setup_step_action_text_size">18sp</dimen>
diff --git a/java/res/values-h520dp-land/setup-dimens-small-tablet-land.xml b/java/res/values-h520dp-land/setup-dimens-small-tablet-land.xml
index aedf79f..a0e30cd 100644
--- a/java/res/values-h520dp-land/setup-dimens-small-tablet-land.xml
+++ b/java/res/values-h520dp-land/setup-dimens-small-tablet-land.xml
@@ -20,7 +20,6 @@
     <dimen name="setup_welcome_description_text_size">32sp</dimen>
     <dimen name="setup_step_bullet_text_size">24sp</dimen>
     <dimen name="setup_step_triangle_indicator_height">24dp</dimen>
-    <dimen name="setup_step_indicator_height">24dp</dimen>
     <dimen name="setup_step_title_text_size">24sp</dimen>
     <dimen name="setup_step_instruction_text_size">18sp</dimen>
     <dimen name="setup_step_action_text_size">20sp</dimen>
diff --git a/java/res/values-h540dp-port/setup-dimens-large-phone-port.xml b/java/res/values-h540dp-port/setup-dimens-large-phone-port.xml
index 6d66f46..cf2a10a 100644
--- a/java/res/values-h540dp-port/setup-dimens-large-phone-port.xml
+++ b/java/res/values-h540dp-port/setup-dimens-large-phone-port.xml
@@ -20,7 +20,6 @@
     <dimen name="setup_welcome_description_text_size">26sp</dimen>
     <dimen name="setup_step_bullet_text_size">22sp</dimen>
     <dimen name="setup_step_triangle_indicator_height">24dp</dimen>
-    <dimen name="setup_step_indicator_height">24dp</dimen>
     <dimen name="setup_step_title_text_size">20sp</dimen>
     <dimen name="setup_step_instruction_text_size">16sp</dimen>
     <dimen name="setup_step_action_text_size">18sp</dimen>
diff --git a/java/res/values-h720dp-land/setup-dimens-large-tablet-land.xml b/java/res/values-h720dp-land/setup-dimens-large-tablet-land.xml
index e22b741..a782ef8 100644
--- a/java/res/values-h720dp-land/setup-dimens-large-tablet-land.xml
+++ b/java/res/values-h720dp-land/setup-dimens-large-tablet-land.xml
@@ -20,7 +20,6 @@
     <dimen name="setup_welcome_description_text_size">38sp</dimen>
     <dimen name="setup_step_bullet_text_size">24sp</dimen>
     <dimen name="setup_step_triangle_indicator_height">24dp</dimen>
-    <dimen name="setup_step_indicator_height">24dp</dimen>
     <dimen name="setup_step_title_text_size">24sp</dimen>
     <dimen name="setup_step_instruction_text_size">18sp</dimen>
     <dimen name="setup_step_action_text_size">20sp</dimen>
diff --git a/java/res/values-h800dp-port/setup-dimens-small-tablet-port.xml b/java/res/values-h800dp-port/setup-dimens-small-tablet-port.xml
index 86cf3a0..9ac0f11 100644
--- a/java/res/values-h800dp-port/setup-dimens-small-tablet-port.xml
+++ b/java/res/values-h800dp-port/setup-dimens-small-tablet-port.xml
@@ -20,7 +20,6 @@
     <dimen name="setup_welcome_description_text_size">36sp</dimen>
     <dimen name="setup_step_bullet_text_size">24sp</dimen>
     <dimen name="setup_step_triangle_indicator_height">24dp</dimen>
-    <dimen name="setup_step_indicator_height">24dp</dimen>
     <dimen name="setup_step_title_text_size">24sp</dimen>
     <dimen name="setup_step_instruction_text_size">18sp</dimen>
     <dimen name="setup_step_action_text_size">20sp</dimen>
diff --git a/java/res/values-land/setup-dimens-small-phone-land.xml b/java/res/values-land/setup-dimens-small-phone-land.xml
index 088e656..de93eee 100644
--- a/java/res/values-land/setup-dimens-small-phone-land.xml
+++ b/java/res/values-land/setup-dimens-small-phone-land.xml
@@ -20,7 +20,6 @@
     <dimen name="setup_welcome_description_text_size">18sp</dimen>
     <dimen name="setup_step_bullet_text_size">18sp</dimen>
     <dimen name="setup_step_triangle_indicator_height">18dp</dimen>
-    <dimen name="setup_step_indicator_height">18dp</dimen>
     <dimen name="setup_step_title_text_size">18sp</dimen>
     <dimen name="setup_step_instruction_text_size">14sp</dimen>
     <dimen name="setup_step_action_text_size">16sp</dimen>
diff --git a/java/res/values-port/setup-dimens-small-phone-port.xml b/java/res/values-port/setup-dimens-small-phone-port.xml
index 8ac72ea..cf2751f 100644
--- a/java/res/values-port/setup-dimens-small-phone-port.xml
+++ b/java/res/values-port/setup-dimens-small-phone-port.xml
@@ -20,7 +20,6 @@
     <dimen name="setup_welcome_description_text_size">20sp</dimen>
     <dimen name="setup_step_bullet_text_size">18sp</dimen>
     <dimen name="setup_step_triangle_indicator_height">18dp</dimen>
-    <dimen name="setup_step_indicator_height">18dp</dimen>
     <dimen name="setup_step_title_text_size">18sp</dimen>
     <dimen name="setup_step_instruction_text_size">14sp</dimen>
     <dimen name="setup_step_action_text_size">16sp</dimen>
diff --git a/java/res/values-sw540dp/config.xml b/java/res/values-sw540dp/config.xml
index b1e5783..f1d6505 100644
--- a/java/res/values-sw540dp/config.xml
+++ b/java/res/values-sw540dp/config.xml
@@ -23,9 +23,6 @@
     <!-- Whether or not Popup on key press is enabled by default -->
     <bool name="config_default_key_preview_popup">false</bool>
     <bool name="config_default_sound_enabled">true</bool>
-    <bool name="config_auto_correction_spacebar_led_enabled">false</bool>
-    <!-- The language is never displayed if == 0, always displayed if < 0 -->
-    <integer name="config_delay_before_fadeout_language_on_spacebar">1200</integer>
     <integer name="config_max_more_keys_column">5</integer>
     <!--
         Configuration for MainKeyboardView
diff --git a/java/res/values-sw540dp/dimens.xml b/java/res/values-sw540dp/dimens.xml
index 801b7ac..3fbdbe8 100644
--- a/java/res/values-sw540dp/dimens.xml
+++ b/java/res/values-sw540dp/dimens.xml
@@ -80,8 +80,6 @@
     <dimen name="suggestion_text_size">22dp</dimen>
     <dimen name="more_suggestions_hint_text_size">33dp</dimen>
 
-    <!-- Gesture trail parameters -->
-    <dimen name="gesture_trail_width">2.5dp</dimen>
     <!-- Gesture floating preview text parameters -->
     <dimen name="gesture_floating_preview_text_size">28dp</dimen>
     <dimen name="gesture_floating_preview_text_offset">87dp</dimen>
diff --git a/java/res/values-sw768dp/config.xml b/java/res/values-sw768dp/config.xml
index a3f5de9..4d3f29d 100644
--- a/java/res/values-sw768dp/config.xml
+++ b/java/res/values-sw768dp/config.xml
@@ -24,7 +24,6 @@
     <!-- Whether or not Popup on key press is enabled by default -->
     <bool name="config_default_key_preview_popup">false</bool>
     <bool name="config_default_sound_enabled">true</bool>
-    <bool name="config_auto_correction_spacebar_led_enabled">false</bool>
     <integer name="config_max_more_keys_column">5</integer>
     <!--
         Configuration for MainKeyboardView
diff --git a/java/res/values-sw768dp/dimens.xml b/java/res/values-sw768dp/dimens.xml
index 4671aa2..f0d53e7 100644
--- a/java/res/values-sw768dp/dimens.xml
+++ b/java/res/values-sw768dp/dimens.xml
@@ -80,8 +80,6 @@
     <dimen name="suggestion_text_size">22dp</dimen>
     <dimen name="more_suggestions_hint_text_size">33dp</dimen>
 
-    <!-- Gesture trail parameters -->
-    <dimen name="gesture_trail_width">2.5dp</dimen>
     <!-- Gesture floating preview text parameters -->
     <dimen name="gesture_floating_preview_text_size">26dp</dimen>
     <dimen name="gesture_floating_preview_text_offset">86dp</dimen>
diff --git a/java/res/values/config.xml b/java/res/values/config.xml
index 669a661..3b989ee 100644
--- a/java/res/values/config.xml
+++ b/java/res/values/config.xml
@@ -22,8 +22,6 @@
     <bool name="config_use_fullscreen_mode">false</bool>
     <bool name="config_enable_show_voice_key_option">true</bool>
     <bool name="config_enable_show_option_of_key_preview_popup">true</bool>
-    <!-- TODO: Disable the following configuration for production. -->
-    <bool name="config_enable_usability_study_mode_option">true</bool>
     <!-- Whether or not Popup on key press is enabled by default -->
     <bool name="config_default_key_preview_popup">true</bool>
     <!-- Default value for next word prediction: after entering a word and a space only, should we look
diff --git a/java/res/values/dimens.xml b/java/res/values/dimens.xml
index 4588b10..94554ae 100644
--- a/java/res/values/dimens.xml
+++ b/java/res/values/dimens.xml
@@ -80,7 +80,6 @@
     <dimen name="more_suggestions_row_height">40dp</dimen>
     <dimen name="more_suggestions_bottom_gap">6dp</dimen>
     <dimen name="more_suggestions_modal_tolerance">32.0dp</dimen>
-    <dimen name="more_suggestions_slide_allowance">16.0dp</dimen>
     <integer name="max_more_suggestions_row">6</integer>
     <fraction name="min_more_suggestions_width">90%</fraction>
     <fraction name="more_suggestions_info_ratio">18%</fraction>
diff --git a/java/res/xml/key_symbols_period.xml b/java/res/xml/key_symbols_period.xml
deleted file mode 100644
index 6efc9de..0000000
--- a/java/res/xml/key_symbols_period.xml
+++ /dev/null
@@ -1,47 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-/*
-**
-** Copyright 2013, The Android Open Source Project
-**
-** Licensed under the Apache License, Version 2.0 (the "License");
-** you may not use this file except in compliance with the License.
-** You may obtain a copy of the License at
-**
-**     http://www.apache.org/licenses/LICENSE-2.0
-**
-** Unless required by applicable law or agreed to in writing, software
-** distributed under the License is distributed on an "AS IS" BASIS,
-** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-** See the License for the specific language governing permissions and
-** limitations under the License.
-*/
--->
-
-<merge
-    xmlns:latin="http://schemas.android.com/apk/res/com.android.inputmethod.latin"
->
-    <!-- U+2105: "℅" CARE OF
-         U+2122: "™" TRADE MARK SIGN
-         U+00AE: "®" REGISTERED SIGN
-         U+00A9: "©" COPYRIGHT SIGN
-         U+00A7: "§" SECTION SIGN
-         U+00B6: "¶" PILCROW SIGN
-         U+002C: "," COMMA
-         U+2022: "•" BULLET -->
-    <!-- U+00B0: "°" DEGREE SIGN
-         U+2032: "′" PRIME
-         U+2033: "″" DOUBLE PRIME
-         U+2191: "↑" UPWARDS ARROW
-         U+2193: "↓" DOWNWARDS ARROW
-         U+2190: "←" LEFTWARDS ARROW
-         U+2192: "→" RIGHTWARDS ARROW
-         U+2026: "…" HORIZONTAL ELLIPSIS -->
-    <!-- U+0394: "Δ" GREEK CAPITAL LETTER DELTA
-         U+03A0: "Π" GREEK CAPITAL LETTER PI
-         U+03C0: "π" GREEK SMALL LETTER PI -->
-    <Key
-        latin:keyLabel="."
-        latin:keyLabelFlags="hasPopupHint"
-        latin:moreKeys="!fixedColumnOrder!8,&#x2105;,&#x2122;,&#x00AE;,&#x00A9;,&#x00A7;,&#x00B6;,\\,,&#x2022;,&#x00B0;,&#x2032;,&#x2033;,&#x2191;,&#x2193;,&#x2190;,&#x2192;,&#x2026;,!text/more_keys_for_bullet,&#x0394;,&#x03A0;,&#x03C0;" />
-</merge>