Move WebMIMERegistry impl from //content to blink:platform/network/mime

third_party/WebKit/public/platform/Platform.h

Index: third_party/WebKit/public/platform/Platform.h
diff --git a/third_party/WebKit/public/platform/Platform.h b/third_party/WebKit/public/platform/Platform.h
index 708d13a5988ae19bc6b5876588d6952df00122d6..747885a940b479fac6bcd5a2f069c40775d78f50 100644
--- a/third_party/WebKit/public/platform/Platform.h
+++ b/third_party/WebKit/public/platform/Platform.h
@@ -98,7 +98,6 @@ class WebMediaStreamCenter;
 class WebMediaStreamCenterClient;
 class WebMediaStreamTrack;
 class WebMessagePortChannel;
-class WebMimeRegistry;
 class WebNotificationManager;
 class WebPluginListBuilder;
 class WebPrescientNetworking;
@@ -154,9 +153,6 @@ class BLINK_PLATFORM_EXPORT Platform {
   // Must return non-null.
   virtual WebFileUtilities* fileUtilities() { return nullptr; }
 
-  // Must return non-null.
-  virtual WebMimeRegistry* mimeRegistry() { return nullptr; }
-
   // May return null if sandbox support is not necessary
   virtual WebSandboxSupport* sandboxSupport() { return nullptr; }