Use WebViewClient instead of BlinkPlatform for screen lock.

public/web/WebViewClient.h

Index: public/web/WebViewClient.h
diff --git a/public/web/WebViewClient.h b/public/web/WebViewClient.h
index 6f041e7a1ec2e65955ea641c1aadcaf772d4f459..0b0631cde9af455356874ecf75533f1e155b698b 100644
--- a/public/web/WebViewClient.h
+++ b/public/web/WebViewClient.h
@@ -68,6 +68,7 @@ class WebNode;
 class WebPushClient;
 class WebRange;
 class WebSpeechRecognizer;
+class WebScreenOrientationClient;
 class WebStorageNamespace;
 class WebURL;
 class WebURLRequest;
@@ -301,10 +302,19 @@ public:
 
     virtual WebMIDIClient* webMIDIClient() { return 0; }
 
+
     // Push Messaging -------------------------------------------------------
 
     virtual WebPushClient* webPushClient() { return 0; }
 
+    // Screen Orientation ---------------------------------------------------
+
+    virtual WebScreenOrientationClient* webScreenOrientationClient()
+    {
+        return 0;
+    }
+
+
     // Content detection ----------------------------------------------------
 
     // Retrieves detectable content (e.g., email addresses, phone numbers)