Add FakeClipboard implementation for unit tests.

ui/base/clipboard/clipboard.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_BASE_CLIPBOARD_CLIPBOARD_H_
 #define UI_BASE_CLIPBOARD_CLIPBOARD_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
+#include "base/lazy_instance.h"
 #include "base/memory/shared_memory.h"
 #include "base/process/process.h"
 #include "base/strings/string16.h"
+#include "base/synchronization/lock.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread_checker.h"
 #include "ui/base/clipboard/clipboard_types.h"
 #include "ui/base/ui_base_export.h"
 
 #if defined(OS_WIN)
 #include <objidl.h>
 #endif
 
 namespace base {
@@ skipping 17 matching lines @@
 
 #ifdef __OBJC__
 @class NSString;
 #else
 class NSString;
 #endif
 
 namespace ui {
 template <typename T>
 class ClipboardTest;
+class FakeClipboard;
 class ScopedClipboardWriter;
 
 class UI_BASE_EXPORT Clipboard : NON_EXPORTED_BASE(public base::ThreadChecker) {
  public:
   // MIME type constants.
   static const char kMimeTypeText[];
   static const char kMimeTypeURIList[];
   static const char kMimeTypeDownloadURL[];
   static const char kMimeTypeHTML[];
   static const char kMimeTypeRTF[];
   static const char kMimeTypePNG[];
 
   // Platform neutral holder for native data representation of a clipboard type.
   struct UI_BASE_EXPORT FormatType {
     FormatType();
     ~FormatType();
 
     // Serializes and deserializes a FormatType for use in IPC messages.
     std::string Serialize() const;
     static FormatType Deserialize(const std::string& serialization);
 
-#if !defined(OS_ANDROID)
     // FormatType can be used in a set on some platforms.
     bool operator<(const FormatType& other) const;
-#endif
 
 #if defined(OS_WIN)
     const FORMATETC& ToFormatEtc() const { return data_; }
 #elif defined(USE_AURA) || defined(OS_ANDROID)
     const std::string& ToString() const { return data_; }
 #elif defined(OS_MACOSX)
     NSString* ToNSString() const { return data_; }
     // Custom copy and assignment constructor to handle NSString.
     FormatType(const FormatType& other);
     FormatType& operator=(const FormatType& other);
@@ skipping 92 matching lines @@
       const std::vector<base::PlatformThreadId>& allowed_threads);
 
   // Returns the clipboard object for the current thread.
   //
   // Most implementations will have at most one clipboard which will live on
   // the main UI thread, but Windows has tricky semantics where there have to
   // be two clipboards: one that lives on the UI thread and one that lives on
   // the IO thread.
   static Clipboard* GetForCurrentThread();
 
+  // Testing helper to Replace any clipboard for the current thread with a fake

[sky, 2014/11/14 02:10:31]

Why the caps for Replace?

[dcheng, 2014/11/14 03:30:28]

Done.

+  // clipboard. Useful for unit tests, since those generally run in parallel.
+  static void UseFakeForCurrentThreadForTest();

[sky, 2014/11/14 02:10:31]

How about UseTestClipboardForCurrentThread? Or Mock if you prefer. But I think
Test better matches what it is.

[dcheng, 2014/11/14 03:30:28]

Done.

+
   // Destroys the clipboard for the current thread. Usually, this will clean up
   // all clipboards, except on Windows. (Previous code leaks the IO thread
   // clipboard, so it shouldn't be a problem.)
   static void DestroyClipboardForCurrentThread();
 
   // Returns a sequence number which uniquely identifies clipboard state.
   // This can be used to version the data on the clipboard and determine
   // whether it has changed.
-  virtual uint64 GetSequenceNumber(ClipboardType type) = 0;
+  virtual uint64 GetSequenceNumber(ClipboardType type) const = 0;
 
   // Tests whether the clipboard contains a certain format
   virtual bool IsFormatAvailable(const FormatType& format,
                                  ClipboardType type) const = 0;
 
   // Clear the clipboard data.
   virtual void Clear(ClipboardType type) = 0;
 
   virtual void ReadAvailableTypes(ClipboardType type,
                                   std::vector<base::string16>* types,
@@ skipping 110 matching lines @@
                          size_t data_len) = 0;
 
  private:
   template <typename T>
   friend class ClipboardTest;
   // For access to WriteObjects().
   // TODO(dcheng): Remove the temporary exception for content.
   friend class content::ClipboardMessageFilter;
   friend class ScopedClipboardWriter;
 
+  // A list of allowed threads. By default, this is empty and no thread checking
+  // is done (in the unit test case), but a user (like content) can set which
+  // threads are allowed to call this method.
+  typedef std::vector<base::PlatformThreadId> AllowedThreadsVector;
+  static base::LazyInstance<AllowedThreadsVector> allowed_threads_;
+
+  // Mapping from threads to clipboard objects.
+  typedef std::map<base::PlatformThreadId, Clipboard*> ClipboardMap;
+  static base::LazyInstance<ClipboardMap> clipboard_map_;
+
+  // Mutex that controls access to |g_clipboard_map|.
+  static base::LazyInstance<base::Lock>::Leaky clipboard_map_lock_;
+
   DISALLOW_COPY_AND_ASSIGN(Clipboard);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_CLIPBOARD_CLIPBOARD_H_