WebCrypto: Add SHA-1 support to crypto.subtle.digest().

public/platform/Platform.h

Index: public/platform/Platform.h
diff --git a/public/platform/Platform.h b/public/platform/Platform.h
index e1c18200150232b48270ab37f8e92e77fb5a9dab..2ce3567152994d1b80b90e7d6449571c2e8a26ee 100644
--- a/public/platform/Platform.h
+++ b/public/platform/Platform.h
@@ -55,6 +55,7 @@ class WebContentDecryptionModule;
 class WebClipboard;
 class WebCompositorSupport;
 class WebCookieJar;
+class WebCrypto;
 class WebDeviceMotionListener;
 class WebDiscardableMemory;
 class WebFallbackThemeEngine;
@@ -542,12 +543,15 @@ public:
     // May return null if WebRTC functionality is not avaliable or out of resources.
     virtual WebMediaStreamCenter* createMediaStreamCenter(WebMediaStreamCenterClient*) { return 0; }
 
-
     // WebWorker ----------------------------------------------------------
 
     virtual void didStartWorkerRunLoop(const WebWorkerRunLoop&) { }
     virtual void didStopWorkerRunLoop(const WebWorkerRunLoop&) { }
 
+    // WebCrypto ----------------------------------------------------------
+
+    // May return 0.
+    virtual WebCrypto* crypto() { return 0; }
 
     // Device Motion / Orientation ----------------------------------------