Prepare to get the multiprocess setting from WebViewDelegate.

In future OS versions, we should fetch the multiprocess-enabled setting
from WebViewDelegate instead of querying the setting directly. Add the
skeleton code to get this from the delegate under a build version
condition.

BUG=684489

Review-Url: https://codereview.chromium.org/2645413002
Cr-Commit-Position: refs/heads/master@{#445705}
(cherry picked from commit acc84fb)

Review-Url: https://codereview.chromium.org/2649273004 .
Cr-Commit-Position: refs/branch-heads/2987@{#56}
Cr-Branched-From: ad51088-refs/heads/master@{#444943}

Author: tornewuff

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

@@ -50,6 +50,7 @@
 import org.chromium.android_webview.PlatformServiceBridge;
 import org.chromium.android_webview.ResourcesContextWrapperFactory;
 import org.chromium.base.BuildConfig;
+import org.chromium.base.BuildInfo;
 import org.chromium.base.CommandLine;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.MemoryPressureListener;
@@ -198,6 +199,13 @@ public WebViewChromiumFactoryProvider(android.webkit.WebViewDelegate delegate) {
         initialize(WebViewDelegateFactory.createProxyDelegate(delegate));
     }
 
+    /**
+     * Constructor for internal use when a proxy delegate has already been created.
+     */
+    WebViewChromiumFactoryProvider(WebViewDelegate delegate) {
+        initialize(delegate);
+    }
+
     @SuppressFBWarnings("DMI_HARDCODED_ABSOLUTE_FILENAME")
     private void initialize(WebViewDelegate webViewDelegate) {
         mWebViewDelegate = webViewDelegate;
@@ -225,9 +233,17 @@ private void initialize(WebViewDelegate webViewDelegate) {
             CommandLine.init(null);
         }
 
-        if (Settings.Global.getInt(ContextUtils.getApplicationContext().getContentResolver(),
-                    Settings.Global.WEBVIEW_MULTIPROCESS, 0)
-                == 1) {
+        boolean multiProcess = false;
+        if (BuildInfo.isAtLeastO()) {
+            // Ask the system if multiprocess should be enabled on O+.
+            multiProcess = mWebViewDelegate.isMultiProcessEnabled();
+        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            // Check the multiprocess developer setting directly on N.
+            multiProcess = Settings.Global.getInt(
+                    ContextUtils.getApplicationContext().getContentResolver(),
+                    Settings.Global.WEBVIEW_MULTIPROCESS, 0) == 1;
+        }
+        if (multiProcess) {
             CommandLine cl = CommandLine.getInstance();
             cl.appendSwitch("webview-sandboxed-renderer");
         }

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

@@ -82,6 +82,9 @@ void invokeDrawGlFunctor(
 
         /** @see android.webkit.WebViewDelegate#addWebViewAssetPath */
         void addWebViewAssetPath(Context context);
+
+        /** @see android.webkit.WebViewDelegate#isMultiProcessEnabled */
+        boolean isMultiProcessEnabled();
     }
 
     /**
@@ -110,7 +113,7 @@ static WebViewDelegate createApi21CompatibilityDelegate() {
      * 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 {
         android.webkit.WebViewDelegate mDelegate;
 
         ProxyDelegate(android.webkit.WebViewDelegate delegate) {
@@ -198,6 +201,11 @@ public AssetManager getAssets() {
                 }
             });
         }
+
+        @Override
+        public boolean isMultiProcessEnabled() {
+            throw new UnsupportedOperationException();
+        }
     }
 
     /**
@@ -383,5 +391,10 @@ public void addWebViewAssetPath(Context context) {
                 throw new RuntimeException("Invalid reflection", e);
             }
         }
+
+        @Override
+        public boolean isMultiProcessEnabled() {
+            throw new UnsupportedOperationException();
+        }
     }
 }