[WebAPK] Remove the server URL from public chromium

Tested by running chrome_apk and chrome_public_apk

Bug: 1045009, 911900
Change-Id: Ib6803cfc0668967efdaac147e4d3c3269634c6f5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2126929Reviewed-by: Yusuf Ozuysal <yusufo@chromium.org>
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#757004}

chrome/android/java/src/org/chromium/chrome/browser/AppHooks.java

@@ -375,6 +375,6 @@ public abstract class AppHooks {
      * Returns the URL to the WebAPK creation/update server.
      */
     public String getWebApkServerUrl() {
-        return "https://webapk.googleapis.com/v1/webApks/?alt=proto&key=AIzaSyAoI6v-F31-3t9NunLYEiKcPIqgTJIUZBw";
+        return "";
     }
 }

chrome/browser/android/webapk/webapk_installer.cc

@@ -538,6 +538,11 @@ void WebApkInstaller::InstallAsync(const ShortcutInfo& shortcut_info,
   finish_callback_ = std::move(finish_callback);
   task_type_ = INSTALL;
 
+  if (!server_url_.is_valid()) {
+    OnResult(WebApkInstallResult::FAILURE);
+    return;
+  }
+
   CheckFreeSpace();
 }
 
@@ -574,6 +579,11 @@ void WebApkInstaller::UpdateAsync(const base::FilePath& update_request_path,
   finish_callback_ = std::move(finish_callback);
   task_type_ = UPDATE;
 
+  if (!server_url_.is_valid()) {
+    OnResult(WebApkInstallResult::FAILURE);
+    return;
+  }
+
   base::PostTaskAndReplyWithResult(
       GetBackgroundTaskRunner().get(), FROM_HERE,
       base::BindOnce(&ReadFileInBackground, update_request_path),
@@ -692,6 +702,8 @@ void WebApkInstaller::OnGotIconMurmur2Hashes(
 
 void WebApkInstaller::SendRequest(
     std::unique_ptr<std::string> serialized_proto) {
+  DCHECK(server_url_.is_valid());
+
   timer_.Start(
       FROM_HERE, base::TimeDelta::FromMilliseconds(webapk_server_timeout_ms_),
       base::Bind(&WebApkInstaller::OnResult, weak_ptr_factory_.GetWeakPtr(),