webview: Move downstream code dependency.

Move the dependency on downstream code needed for new Android releases
from the APK target to the WebView Java target. This ensures that
monochrome_public will also get the dependency when appropriate, and
removes the need to duplicate this condition in the downstream targets.

Bug: 1106471
Change-Id: Idc9938eb5dc7f0738f539ac8561bab7abc52f0af
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2309810
Auto-Submit: Richard Coles <torne@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#790401}

android_webview/BUILD.gn

@@ -360,6 +360,11 @@ java_group("android_webview_no_weblayer_java") {
     "//android_webview/nonembedded:nonembedded_java",
     "//android_webview/support_library:support_lib_glue_java",
   ]
+
+  # If the R SDK isn't public yet, include the downstream code to support R.
+  if (!public_android_sdk && android_sdk_release == "r") {
+    deps += [ "//clank/android_webview/next:r_sdk_java" ]
+  }
 }
 
 # Contains all Java dependencies used by WebView.

android_webview/system_webview_apk_tmpl.gni

@@ -48,11 +48,6 @@ template("system_webview_apk_or_module_tmpl") {
       "//android_webview:pak_file_assets",
     ]
 
-    # If the R SDK isn't public yet, include the downstream code to support R.
-    if (!public_android_sdk && android_sdk_release == "r") {
-      deps += [ "//clank/android_webview/next:r_sdk_java" ]
-    }
-
     if (_exclude_weblayer_java) {
       deps += [ "//android_webview:android_webview_no_weblayer_java" ]
     } else {