Add a few missing overrides found by a new clang warning.

ui/base/dragdrop/os_exchange_data_provider_win.h

Index: ui/base/dragdrop/os_exchange_data_provider_win.h
diff --git a/ui/base/dragdrop/os_exchange_data_provider_win.h b/ui/base/dragdrop/os_exchange_data_provider_win.h
index 8587bd1bbacc9b46b3f4a7213080614345851a21..7889157ec9c1ff6331d9759568917d5550041f5f 100644
--- a/ui/base/dragdrop/os_exchange_data_provider_win.h
+++ b/ui/base/dragdrop/os_exchange_data_provider_win.h
@@ -148,39 +148,41 @@ class UI_BASE_EXPORT OSExchangeDataProviderWin
   IDataObjectAsyncCapability* async_operation() const { return data_.get(); }
 
   // OSExchangeData::Provider methods.

[sky, 2014/10/30 00:59:10]

I thought we were getting rid of virtual too?

[Nico, 2014/10/30 01:00:01]

Yes, dcheng is doing this in a separate pass, using automated tooling. I think
today the plugin still insists on virtual.

-  virtual Provider* Clone() const;
-  virtual void MarkOriginatedFromRenderer();
-  virtual bool DidOriginateFromRenderer() const;
-  virtual void SetString(const base::string16& data);
-  virtual void SetURL(const GURL& url, const base::string16& title);
-  virtual void SetFilename(const base::FilePath& path);
-  virtual void SetFilenames(const std::vector<FileInfo>& filenames);
+  virtual Provider* Clone() const override;
+  virtual void MarkOriginatedFromRenderer() override;
+  virtual bool DidOriginateFromRenderer() const override;
+  virtual void SetString(const base::string16& data) override;
+  virtual void SetURL(const GURL& url, const base::string16& title) override;
+  virtual void SetFilename(const base::FilePath& path) override;
+  virtual void SetFilenames(const std::vector<FileInfo>& filenames) override;
   virtual void SetPickledData(const OSExchangeData::CustomFormat& format,
-                              const Pickle& data);
+                              const Pickle& data) override;
   virtual void SetFileContents(const base::FilePath& filename,
-                               const std::string& file_contents);
-  virtual void SetHtml(const base::string16& html, const GURL& base_url);
+                               const std::string& file_contents) override;
+  virtual void SetHtml(const base::string16& html,
+                       const GURL& base_url) override;
 
-  virtual bool GetString(base::string16* data) const;
+  virtual bool GetString(base::string16* data) const override;
   virtual bool GetURLAndTitle(OSExchangeData::FilenameToURLPolicy policy,
                               GURL* url,
-                              base::string16* title) const;
-  virtual bool GetFilename(base::FilePath* path) const;
-  virtual bool GetFilenames(std::vector<FileInfo>* filenames) const;
+                              base::string16* title) const override;
+  virtual bool GetFilename(base::FilePath* path) const override;
+  virtual bool GetFilenames(std::vector<FileInfo>* filenames) const override;
   virtual bool GetPickledData(const OSExchangeData::CustomFormat& format,
-                              Pickle* data) const;
+                              Pickle* data) const override;
   virtual bool GetFileContents(base::FilePath* filename,
-                               std::string* file_contents) const;
-  virtual bool GetHtml(base::string16* html, GURL* base_url) const;
-  virtual bool HasString() const;
-  virtual bool HasURL(OSExchangeData::FilenameToURLPolicy policy) const;
-  virtual bool HasFile() const;
-  virtual bool HasFileContents() const;
-  virtual bool HasHtml() const;
+                               std::string* file_contents) const override;
+  virtual bool GetHtml(base::string16* html, GURL* base_url) const override;
+  virtual bool HasString() const override;
+  virtual bool HasURL(
+      OSExchangeData::FilenameToURLPolicy policy) const override;
+  virtual bool HasFile() const override;
+  virtual bool HasFileContents() const override;
+  virtual bool HasHtml() const override;
   virtual bool HasCustomFormat(
-      const OSExchangeData::CustomFormat& format) const;
+      const OSExchangeData::CustomFormat& format) const override;
   virtual void SetDownloadFileInfo(
-      const OSExchangeData::DownloadFileInfo& download_info);
+      const OSExchangeData::DownloadFileInfo& download_info) override;
   virtual void SetDragImage(const gfx::ImageSkia& image,
                             const gfx::Vector2d& cursor_offset) override;
   virtual const gfx::ImageSkia& GetDragImage() const override;