Send all of the icon URLs listed in Web Manifest to WebAPK Server.

chrome/android/webapk/shell_apk/BUILD.gn

Index: chrome/android/webapk/shell_apk/BUILD.gn
diff --git a/chrome/android/webapk/shell_apk/BUILD.gn b/chrome/android/webapk/shell_apk/BUILD.gn
index fb6fabed50357b3b602de6db31d4302a82111f36..7ffcabf48d1278422baef254e2a4381554a7361f 100644
--- a/chrome/android/webapk/shell_apk/BUILD.gn
+++ b/chrome/android/webapk/shell_apk/BUILD.gn
@@ -16,6 +16,11 @@ declare_args() {
   # The Url of the Web Manifest file.
   webapk_web_manifest_url = "https://www.template.com/manifest.json"
 
+  # Murmur2 hash of the homescreen icon. The hash should be of the icon as it is
+  # available from the web. The icon bytes should not be transformed (e.g.
+  # decoded / encoded) prior to taking the hash.
+  webapk_icon_murmur2_hash = "0"
+
   # Attributes from Web Manifest.
   webapk_start_url = "https://www.template.com/home_page"
   webapk_name = "Longer Sample WebAPK Name"
@@ -25,14 +30,7 @@ declare_args() {
   webapk_orientation = "portrait"
   webapk_theme_color = "2147483648L"  # HostBrowserLauncher#MANIFEST_COLOR_INVALID_OR_MISSING
   webapk_background_color = "2147483648L"  #HostBrowserLauncher#MANIFEST_COLOR_INVALID_OR_MISSING
-
-  # The URL of the app icon. Empty if the app icon is generated.
-  webapk_icon_url = "http://www.template.com/icon.png"
-
-  # Murmur2 hash of the homescreen icon. The hash should be of the icon as it is
-  # available from the web. The icon bytes should not be transformed (e.g.
-  # decoded / encoded) prior to taking the hash.
-  webapk_icon_murmur2_hash = "0L"
+  webapk_icon_urls_and_icon_murmur2_hashes = "http://www.template.com/icon1.png $webapk_icon_murmur2_hash http://www.template.com/icon2.png $webapk_icon_murmur2_hash"
 
   # Host part of |webapk_scope_url|.
   webapk_scope_url_host = "www.template.com"
@@ -68,8 +66,7 @@ jinja_template("shell_apk_manifest") {
     "orientation=$webapk_orientation",
     "theme_color=$webapk_theme_color",
     "background_color=$webapk_background_color",
-    "icon_url=$webapk_icon_url",
-    "icon_murmur2_hash=$webapk_icon_murmur2_hash",
+    "icon_urls_and_icon_murmur2_hashes=$webapk_icon_urls_and_icon_murmur2_hashes",
     "scope_url_host=$webapk_scope_url_host",
     "scope_url_path=$webapk_scope_url_path",
     "web_manifest_url=$webapk_web_manifest_url",