webapps: initial addition of splash screen icon downloading

chrome/android/java/res/values/dimens.xml

Index: chrome/android/java/res/values/dimens.xml
diff --git a/chrome/android/java/res/values/dimens.xml b/chrome/android/java/res/values/dimens.xml
index 225ecd9755a7758abade6e8ba3b0791db615c790..dddd873b72a52e54b63223ada737d0b86c2a86fd 100644
--- a/chrome/android/java/res/values/dimens.xml
+++ b/chrome/android/java/res/values/dimens.xml
@@ -70,7 +70,6 @@
     <dimen name="infobar_icon_size">36dp</dimen>
 
     <!-- App banner dimensions -->
-    <dimen name="app_banner_icon_size">48dp</dimen>
     <dimen name="app_banner_icon_spacing">16dp</dimen>
 
     <!-- Contextual search dimensions -->
@@ -192,6 +191,10 @@
     <dimen name="find_in_page_popup_height">60dp</dimen>
     <dimen name="find_in_page_popup_margin_end">62dp</dimen>
 
+    <!-- Web app dimensions -->
+    <dimen name="webapp_splash_image_size">128dp</dimen>
+    <dimen name="webapp_home_screen_icon_size">48dp</dimen>
+
     <!-- Toolbar dimensions -->
     <dimen name="toolbar_tab_count_text_size_1_digit">12dp</dimen>
     <dimen name="toolbar_tab_count_text_size_2_digit">10dp</dimen>