[webcrypto] Remove the mock implementation of WebCrypto.

content/public/renderer/content_renderer_client.h

Index: content/public/renderer/content_renderer_client.h
diff --git a/content/public/renderer/content_renderer_client.h b/content/public/renderer/content_renderer_client.h
index 06f93e7a010b02c153e79c88f9c3503580c816aa..796778ab4565210fd2ea4aa6cdee75c095c7fb07 100644
--- a/content/public/renderer/content_renderer_client.h
+++ b/content/public/renderer/content_renderer_client.h
@@ -29,7 +29,6 @@ class MessageLoop;
 namespace WebKit {
 class WebAudioDevice;
 class WebClipboard;
-class WebCrypto;
 class WebFrame;
 class WebMIDIAccessor;
 class WebMIDIAccessorClient;
@@ -156,10 +155,6 @@ class CONTENT_EXPORT ContentRendererClient {
   virtual WebKit::WebSpeechSynthesizer* OverrideSpeechSynthesizer(
       WebKit::WebSpeechSynthesizerClient* client);
 
-  // Allows the embedder to override the WebCrypto used.
-  // If it returns NULL the content layer will handle crypto.
-  virtual WebKit::WebCrypto* OverrideWebCrypto();
-
   // Returns true if the renderer process should schedule the idle handler when
   // all widgets are hidden.
   virtual bool RunIdleHandlerWhenWidgetsHidden();