Add Clipboard::GetSequenceNumber test and fix Android.

ui/base/clipboard/clipboard_android.cc

Index: ui/base/clipboard/clipboard_android.cc
diff --git a/ui/base/clipboard/clipboard_android.cc b/ui/base/clipboard/clipboard_android.cc
index e5e2a960d4da4c4558f8e4c115ca8d4ab3bf285e..ea44d4538ef5da987ce35586a4089c96f5c580e2 100644
--- a/ui/base/clipboard/clipboard_android.cc
+++ b/ui/base/clipboard/clipboard_android.cc
@@ -45,7 +45,7 @@ const char kBookmarkFormat[] = "bookmark";
 const char kMimeTypePepperCustomData[] = "chromium/x-pepper-custom-data";
 const char kMimeTypeWebCustomData[] = "chromium/x-web-custom-data";
 
-class ClipboardMap {
+class ClipboardMap : public ClipboardChangeListener {
  public:
   ClipboardMap();
   std::string Get(const std::string& format);
@@ -53,17 +53,23 @@ class ClipboardMap {
   void Set(const std::string& format, const std::string& data);
   void Clear();
 
+  uint64 sequence_number() const { return sequence_number_; }
+
  private:
+  // Called from Java when the clipboard changes.
+  void OnChange(JNIEnv* env, jobject obj) OVERRIDE;
+
   void SyncWithAndroidClipboard();
   std::map<std::string, std::string> map_;
   base::Lock lock_;
 
   // Java class and methods for the Android ClipboardManager.
   ScopedJavaGlobalRef<jobject> clipboard_manager_;
+  uint64 sequence_number_;
 };
 base::LazyInstance<ClipboardMap>::Leaky g_map = LAZY_INSTANCE_INITIALIZER;
 
-ClipboardMap::ClipboardMap() {
+ClipboardMap::ClipboardMap() : sequence_number_(0) {
   JNIEnv* env = AttachCurrentThread();
   DCHECK(env);
 
@@ -75,6 +81,10 @@ ClipboardMap::ClipboardMap() {
       Java_Clipboard_create(env, context);
   DCHECK(local_ref.obj());
   clipboard_manager_.Reset(env, local_ref.Release());
+
+  Java_Clipboard_addChangeListener(
+      env, clipboard_manager_.obj(), reinterpret_cast<intptr_t>(this));
+  LOG(ERROR) << "Hello?";
 }
 
 std::string ClipboardMap::Get(const std::string& format) {
@@ -127,6 +137,12 @@ void ClipboardMap::Clear() {
   Java_Clipboard_setText(env, clipboard_manager_.obj(), NULL);
 }
 
+void ClipboardMap::OnChange(JNIEnv* env, jobject obj) {
+  LOG(ERROR) << "Ping";
+  // TODO(dcheng): We may or may not need a lock here.
+  ++sequence_number_;
+}
+
 // If the internal map contains a plain-text entry and it does not match that
 // in the Android clipboard, clear the map and insert the Android text into it.
 // If there is an HTML entry in the Android clipboard it gets inserted in the
@@ -223,10 +239,7 @@ void Clipboard::WriteObjects(ClipboardType type, const ObjectMap& objects) {
 
 uint64 Clipboard::GetSequenceNumber(ClipboardType /* type */) {
   DCHECK(CalledOnValidThread());
-  // TODO: implement this. For now this interface will advertise
-  // that the clipboard never changes. That's fine as long as we
-  // don't rely on this signal.
-  return 0;
+  return g_map.Get().sequence_number();
 }
 
 bool Clipboard::IsFormatAvailable(const Clipboard::FormatType& format,
@@ -389,6 +402,7 @@ const Clipboard::FormatType& Clipboard::GetPepperCustomDataFormatType() {
 }
 
 void Clipboard::WriteText(const char* text_data, size_t text_len) {
+  DCHECK(CalledOnValidThread());
   g_map.Get().Set(kPlainTextFormat, std::string(text_data, text_len));
 }
 
@@ -396,10 +410,12 @@ void Clipboard::WriteHTML(const char* markup_data,
                           size_t markup_len,
                           const char* url_data,
                           size_t url_len) {
+  DCHECK(CalledOnValidThread());
   g_map.Get().Set(kHTMLFormat, std::string(markup_data, markup_len));
 }
 
 void Clipboard::WriteRTF(const char* rtf_data, size_t data_len) {
+  DCHECK(CalledOnValidThread());
   NOTIMPLEMENTED();
 }
 
@@ -407,18 +423,21 @@ void Clipboard::WriteRTF(const char* rtf_data, size_t data_len) {
 // URL spec.
 void Clipboard::WriteBookmark(const char* title_data, size_t title_len,
                               const char* url_data, size_t url_len) {
+  DCHECK(CalledOnValidThread());
   g_map.Get().Set(kBookmarkFormat, std::string(url_data, url_len));
 }
 
 // Write an extra flavor that signifies WebKit was the last to modify the
 // pasteboard. This flavor has no data.
 void Clipboard::WriteWebSmartPaste() {
+  DCHECK(CalledOnValidThread());
   g_map.Get().Set(kWebKitSmartPasteFormat, std::string());
 }
 
 // Note: we implement this to pass all unit tests but it is currently unclear
 // how some code would consume this.
 void Clipboard::WriteBitmap(const SkBitmap& bitmap) {
+  DCHECK(CalledOnValidThread());
   gfx::Size size(bitmap.width(), bitmap.height());
 
   std::string packed(reinterpret_cast<const char*>(&size), sizeof(size));
@@ -432,6 +451,7 @@ void Clipboard::WriteBitmap(const SkBitmap& bitmap) {
 
 void Clipboard::WriteData(const Clipboard::FormatType& format,
                           const char* data_data, size_t data_len) {
+  DCHECK(CalledOnValidThread());
   g_map.Get().Set(format.data(), std::string(data_data, data_len));
 }