Remove unused code from WebMimeRegistry.

content/renderer/renderer_blink_platform_impl.cc

Index: content/renderer/renderer_blink_platform_impl.cc
diff --git a/content/renderer/renderer_blink_platform_impl.cc b/content/renderer/renderer_blink_platform_impl.cc
index 0c868ec84f85bf96f03b0be2cb882e93b8cdc4ad..c6c147efa16173ec74359d2d3e6da660e00662b4 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -185,7 +185,6 @@ class RendererBlinkPlatformImpl::MimeRegistry
                                    const blink::WebString& codecs) override;
   blink::WebString mimeTypeForExtension(
       const blink::WebString& file_extension) override;
-  blink::WebString mimeTypeFromFile(const blink::WebString& file_path) override;
 };
 
 class RendererBlinkPlatformImpl::FileUtilities : public WebFileUtilitiesImpl {
@@ -513,20 +512,6 @@ WebString RendererBlinkPlatformImpl::MimeRegistry::mimeTypeForExtension(
   return base::ASCIIToUTF16(mime_type);
 }
 
-WebString RendererBlinkPlatformImpl::MimeRegistry::mimeTypeFromFile(
-    const WebString& file_path) {
-  if (IsPluginProcess())
-    return SimpleWebMimeRegistryImpl::mimeTypeFromFile(file_path);
-
-  // The sandbox restricts our access to the registry, so we need to proxy
-  // these calls over to the browser process.
-  std::string mime_type;
-  RenderThread::Get()->Send(new MimeRegistryMsg_GetMimeTypeFromFile(
-      base::FilePath::FromUTF16Unsafe(file_path),
-      &mime_type));
-  return base::ASCIIToUTF16(mime_type);
-}
-
 //------------------------------------------------------------------------------
 
 bool RendererBlinkPlatformImpl::FileUtilities::getFileInfo(