Prepare to get the multiprocess setting from WebViewDelegate.

android_webview/glue/java/src/com/android/webview/chromium/WebViewDelegateFactory.java

Index: android_webview/glue/java/src/com/android/webview/chromium/WebViewDelegateFactory.java
diff --git a/android_webview/glue/java/src/com/android/webview/chromium/WebViewDelegateFactory.java b/android_webview/glue/java/src/com/android/webview/chromium/WebViewDelegateFactory.java
index c2b42958ed57e707d572f8b6e0bcb95b8d528c1e..0bb5c16f2efbb23b1d71fca7d710ff0ee0019726 100644
--- a/android_webview/glue/java/src/com/android/webview/chromium/WebViewDelegateFactory.java
+++ b/android_webview/glue/java/src/com/android/webview/chromium/WebViewDelegateFactory.java
@@ -14,9 +14,12 @@ import android.content.res.Resources;
 import android.graphics.Canvas;
 import android.os.Build;
 import android.os.Trace;
+import android.provider.Settings;
 import android.util.SparseArray;
 import android.view.View;
 
+import org.chromium.base.ContextUtils;
+
 import java.lang.reflect.Method;
 
 /**
@@ -82,6 +85,9 @@ class WebViewDelegateFactory {
 
         /** @see android.webkit.WebViewDelegate#addWebViewAssetPath */
         void addWebViewAssetPath(Context context);
+
+        /** @see android.webkit.WebViewDelegate#isMultiProcessEnabled */
+        boolean isMultiProcessEnabled();
     }
 
     /**
@@ -110,7 +116,7 @@ class WebViewDelegateFactory {
      * A {@link WebViewDelegate com.android.webview.chromium.WebViewDelegate} that proxies requests
      * to a {@link android.webkit.WebViewDelegate android.webkit.WebViewDelegate}.
      */
-    private static class ProxyDelegate implements WebViewDelegate {
+    static class ProxyDelegate implements WebViewDelegate {

[boliu, 2017/01/23 16:34:18]

does protected work here too..?

[Torne, 2017/01/23 17:27:30]

Likewise no point.

         android.webkit.WebViewDelegate mDelegate;
 
         ProxyDelegate(android.webkit.WebViewDelegate delegate) {
@@ -198,6 +204,16 @@ class WebViewDelegateFactory {
                 }
             });
         }
+
+        @Override
+        public boolean isMultiProcessEnabled() {
+            // Multiprocess requires N or later.

[boliu, 2017/01/23 16:34:18]

I suppose this class was never meant to contain implementation, only call
forwarding, although clearly there are exceptions already..

[Torne, 2017/01/23 17:27:30]

I was considering renaming it to Api22AndUpDelegate or something, but I want to
keep this CL minimal for cherrypicking to M57. If you think that's a good idea I
can do it in a followup.

[boliu, 2017/01/23 17:44:04]

Err, no :p

I meant at callsite, have a if <= N, do this, else, call delegate. The reason we
have this thing at all is because the framework delegate didn't exist in api 21.
Above 21, this should behave exactly like the framework delegate, ie some
methods are only safe to call on certain api levels.

That's my mental model anyway.. doesn't matter much either way, since there's
already other implementation here.

[Torne, 2017/01/24 11:24:01]

I think that's a better idea actually; I'll do it that way instead, which means
the initial version of this upstream just won't do anything..

+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) return false;
+
+            // Check the multiprocess developer setting.
+            return Settings.Global.getInt(ContextUtils.getApplicationContext().getContentResolver(),
+                    Settings.Global.WEBVIEW_MULTIPROCESS, 0) == 1;
+        }
     }
 
     /**
@@ -383,5 +399,10 @@ class WebViewDelegateFactory {
                 throw new RuntimeException("Invalid reflection", e);
             }
         }
+
+        @Override
+        public boolean isMultiProcessEnabled() {
+            return false;
+        }
     }
 }