12 files changed, 434 insertions, 214 deletions

diff --git a/chrome/browser/extensions/extension_tts_api.cc b/chrome/browser/extensions/extension_tts_api.cc
index ba9c2f8..b022ec0 100644
--- a/chrome/browser/extensions/extension_tts_api.cc
+++ b/chrome/browser/extensions/extension_tts_api.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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.
 
@@ -6,16 +6,11 @@
 
 #include <string>
 
+#include "base/float_util.h"
 #include "base/values.h"
-#include "base/string_number_conversions.h"
-
-#include "chrome/browser/chromeos/cros/cros_library.h"
-#include "chrome/browser/chromeos/cros/speech_synthesis_library.h"
 
 namespace util = extension_tts_api_util;
 
-using base::DoubleToString;
-
 namespace {
   const char kCrosLibraryNotLoadedError[] =
       "Cros shared library not loaded.";
@@ -23,68 +18,57 @@ namespace {
 
 bool ExtensionTtsSpeakFunction::RunImpl() {
   std::string utterance;
-  std::string options = "";
+  std::string language;
+  std::string gender;
+  double rate = -1.0;
+  double pitch = -1.0;
+  double volume = -1.0;
+
   DictionaryValue* speak_options = NULL;
   EXTENSION_FUNCTION_VALIDATE(args_->GetString(0, &utterance));
+
   if (args_->GetDictionary(1, &speak_options)) {
-    std::string str_value;
-    double real_value;
-    if (speak_options->HasKey(util::kLanguageNameKey) &&
-      speak_options->GetString(util::kLanguageNameKey, &str_value)) {
-        util::AppendSpeakOption(
-            std::string(util::kNameKey), str_value, &options);
+    if (speak_options->HasKey(util::kLanguageNameKey)) {
+      speak_options->GetString(util::kLanguageNameKey, &language);
     }
-    if (speak_options->HasKey(util::kGenderKey) &&
-      speak_options->GetString(util::kGenderKey, &str_value)) {
-        util::AppendSpeakOption(
-            std::string(util::kGenderKey), str_value, &options);
-    }
-    if (util::ReadNumberByKey(speak_options, util::kRateKey, &real_value)) {
-      // The TTS service allows a range of 0 to 5 for speech rate.
-      util::AppendSpeakOption(std::string(util::kRateKey),
-          DoubleToString(real_value * 5), &options);
+
+    if (speak_options->HasKey(util::kGenderKey)) {
+      speak_options->GetString(util::kGenderKey, &gender);
     }
-    if (util::ReadNumberByKey(speak_options, util::kPitchKey, &real_value)) {
-      // The TTS service allows a range of 0 to 2 for speech pitch.
-      util::AppendSpeakOption(std::string(util::kPitchKey),
-          DoubleToString(real_value * 2), &options);
+
+    if (util::ReadNumberByKey(speak_options, util::kRateKey, &rate)) {
+      if (!base::IsFinite(rate) || rate < 0.0 || rate > 1.0) {
+        rate = -1.0;
+      }
     }
-    if (util::ReadNumberByKey(speak_options, util::kVolumeKey, &real_value)) {
-      // The TTS service allows a range of 0 to 5 for speech volume.
-      util::AppendSpeakOption(std::string(util::kVolumeKey),
-          DoubleToString(real_value * 5), &options);
+
+    if (util::ReadNumberByKey(speak_options, util::kPitchKey, &pitch)) {
+      if (!base::IsFinite(pitch) || pitch < 0.0 || pitch > 1.0) {
+        pitch = -1.0;
+      }
     }
-  }
-  if (chromeos::CrosLibrary::Get()->EnsureLoaded()) {
-    if (!options.empty()) {
-      chromeos::CrosLibrary::Get()->GetSpeechSynthesisLibrary()->
-          SetSpeakProperties(options.c_str());
+
+    if (util::ReadNumberByKey(speak_options, util::kVolumeKey, &volume)) {
+      if (!base::IsFinite(volume) || volume < 0.0 || volume > 1.0) {
+        volume = -1.0;
+      }
     }
-    bool ret = chromeos::CrosLibrary::Get()->GetSpeechSynthesisLibrary()->
-        Speak(utterance.c_str());
-    result_.reset();
-    return ret;
   }
-  error_ = kCrosLibraryNotLoadedError;
-  return false;
+
+  ExtensionTtsPlatformImpl* impl = ExtensionTtsPlatformImpl::GetInstance();
+  impl->clear_error();
+  return impl->Speak(utterance, language, gender, rate, pitch, volume);
 }
 
 bool ExtensionTtsStopSpeakingFunction::RunImpl() {
-  if (chromeos::CrosLibrary::Get()->EnsureLoaded()) {
-    return chromeos::CrosLibrary::Get()->GetSpeechSynthesisLibrary()->
-        StopSpeaking();
-  }
-  error_ = kCrosLibraryNotLoadedError;
-  return false;
+  ExtensionTtsPlatformImpl* impl = ExtensionTtsPlatformImpl::GetInstance();
+  impl->clear_error();
+  return impl->StopSpeaking();
 }
 
 bool ExtensionTtsIsSpeakingFunction::RunImpl() {
-  if (chromeos::CrosLibrary::Get()->EnsureLoaded()) {
-    result_.reset(Value::CreateBooleanValue(
-        chromeos::CrosLibrary::Get()->GetSpeechSynthesisLibrary()->
-        IsSpeaking()));
-    return true;
-  }
-  error_ = kCrosLibraryNotLoadedError;
-  return false;
+  ExtensionTtsPlatformImpl* impl = ExtensionTtsPlatformImpl::GetInstance();
+  impl->clear_error();
+  result_.reset(Value::CreateBooleanValue(impl->IsSpeaking()));
+  return true;
 }
diff --git a/chrome/browser/extensions/extension_tts_api.h b/chrome/browser/extensions/extension_tts_api.h
index 84fa384..73fc887 100644
--- a/chrome/browser/extensions/extension_tts_api.h
+++ b/chrome/browser/extensions/extension_tts_api.h
@@ -8,6 +8,46 @@
 #include "chrome/browser/extensions/extension_function.h"
 #include "chrome/browser/extensions/extension_tts_api_util.h"
 
+// Abstract class that defines the native platform TTS interface.
+class ExtensionTtsPlatformImpl {
+ public:
+  static ExtensionTtsPlatformImpl* GetInstance();
+
+  // Speak the given utterance with the given parameters if possible,
+  // and return true on success. Utterance will always be nonempty.
+  // If the user does not specify the other values, language and gender
+  // will be empty strings, and rate, pitch, and volume will be -1.0.
+  virtual bool Speak(
+      const std::string& utterance,
+      const std::string& language,
+      const std::string& gender,
+      double rate,
+      double pitch,
+      double volume) = 0;
+
+  // Stop speaking immediately and return true on success.
+  virtual bool StopSpeaking() = 0;
+
+  // Return true if the synthesis engine is currently speaking.
+  virtual bool IsSpeaking() = 0;
+
+  virtual std::string error() { return error_; }
+  virtual void clear_error() { error_ = std::string(); }
+  virtual void set_error(const std::string& error) { error_ = error; }
+
+ protected:
+  ExtensionTtsPlatformImpl() {}
+  virtual ~ExtensionTtsPlatformImpl() {}
+
+  std::string error_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionTtsPlatformImpl);
+};
+
+//
+// Extension API function definitions
+//
+
 class ExtensionTtsSpeakFunction : public SyncExtensionFunction {
   ~ExtensionTtsSpeakFunction() {}
   virtual bool RunImpl();
diff --git a/chrome/browser/extensions/extension_tts_api_chromeos.cc b/chrome/browser/extensions/extension_tts_api_chromeos.cc
new file mode 100644
index 0000000..a183612
--- /dev/null
+++ b/chrome/browser/extensions/extension_tts_api_chromeos.cc
@@ -0,0 +1,125 @@
+// Copyright (c) 2010 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.
+
+#include "chrome/browser/extensions/extension_tts_api.h"
+
+#include "base/singleton.h"
+#include "base/string_number_conversions.h"
+#include "chrome/browser/chromeos/cros/cros_library.h"
+#include "chrome/browser/chromeos/cros/speech_synthesis_library.h"
+
+namespace util = extension_tts_api_util;
+
+using base::DoubleToString;
+
+namespace {
+const char kCrosLibraryNotLoadedError[] = "Cros shared library not loaded.";
+};
+
+class ExtensionTtsPlatformImplChromeOs : public ExtensionTtsPlatformImpl {
+ public:
+  virtual bool Speak(
+      const std::string& utterance,
+      const std::string& language,
+      const std::string& gender,
+      double rate,
+      double pitch,
+      double volume);
+
+  virtual bool StopSpeaking();
+
+  virtual bool IsSpeaking();
+
+  // Get the single instance of this class.
+  static ExtensionTtsPlatformImplChromeOs* GetInstance();
+
+ private:
+  ExtensionTtsPlatformImplChromeOs() {}
+  virtual ~ExtensionTtsPlatformImplChromeOs() {}
+
+  friend struct DefaultSingletonTraits<ExtensionTtsPlatformImplChromeOs>;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionTtsPlatformImplChromeOs);
+};
+
+// static
+ExtensionTtsPlatformImpl* ExtensionTtsPlatformImpl::GetInstance() {
+  return ExtensionTtsPlatformImplChromeOs::GetInstance();
+}
+
+bool ExtensionTtsPlatformImplChromeOs::Speak(
+    const std::string& utterance,
+    const std::string& language,
+    const std::string& gender,
+    double rate,
+    double pitch,
+    double volume) {
+  chromeos::CrosLibrary* cros_library = chromeos::CrosLibrary::Get();
+  if (!cros_library->EnsureLoaded()) {
+    set_error(kCrosLibraryNotLoadedError);
+    return false;
+  }
+
+  std::string options;
+
+  if (!language.empty()) {
+    util::AppendSpeakOption(
+        std::string(util::kNameKey), language, &options);
+  }
+
+  if (!gender.empty()) {
+    util::AppendSpeakOption(
+        std::string(util::kGenderKey), gender, &options);
+  }
+
+  if (rate >= 0.0) {
+    util::AppendSpeakOption(
+        std::string(util::kRateKey), DoubleToString(rate * 5), &options);
+  }
+
+  if (pitch >= 0.0) {
+    // The TTS service allows a range of 0 to 2 for speech pitch.
+    util::AppendSpeakOption(
+        std::string(util::kPitchKey), DoubleToString(pitch * 2), &options);
+  }
+
+  if (volume >= 0.0) {
+    // The TTS service allows a range of 0 to 5 for speech volume.
+    util::AppendSpeakOption(
+        std::string(util::kVolumeKey), DoubleToString(volume * 5), &options);
+  }
+
+  if (!options.empty()) {
+    cros_library->GetSpeechSynthesisLibrary()->SetSpeakProperties(
+        options.c_str());
+  }
+
+  return cros_library->GetSpeechSynthesisLibrary()->Speak(utterance.c_str());
+}
+
+bool ExtensionTtsPlatformImplChromeOs::StopSpeaking() {
+  if (chromeos::CrosLibrary::Get()->EnsureLoaded()) {
+    return chromeos::CrosLibrary::Get()->GetSpeechSynthesisLibrary()->
+        StopSpeaking();
+  }
+
+  set_error(kCrosLibraryNotLoadedError);
+  return false;
+}
+
+bool ExtensionTtsPlatformImplChromeOs::IsSpeaking() {
+  if (chromeos::CrosLibrary::Get()->EnsureLoaded()) {
+    return chromeos::CrosLibrary::Get()->GetSpeechSynthesisLibrary()->
+        IsSpeaking();
+  }
+
+  set_error(kCrosLibraryNotLoadedError);
+  return false;
+}
+
+// static
+ExtensionTtsPlatformImplChromeOs*
+ExtensionTtsPlatformImplChromeOs::GetInstance() {
+  return Singleton<ExtensionTtsPlatformImplChromeOs>::get();
+}
diff --git a/chrome/browser/extensions/extension_tts_api_gtk.cc b/chrome/browser/extensions/extension_tts_api_gtk.cc
deleted file mode 100644
index 6804f92..0000000
--- a/chrome/browser/extensions/extension_tts_api_gtk.cc
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright (c) 2010 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.

-

-#include "extension_tts_api.h"

-

-bool ExtensionTtsSpeakFunction::RunImpl() {

-  return false;

-}

-

-bool ExtensionTtsStopSpeakingFunction::RunImpl() {

-  return false;

-}

-

-bool ExtensionTtsIsSpeakingFunction::RunImpl() {

-  return false;

-}

diff --git a/chrome/browser/extensions/extension_tts_api_linux.cc b/chrome/browser/extensions/extension_tts_api_linux.cc
new file mode 100644
index 0000000..15f1af1
--- /dev/null
+++ b/chrome/browser/extensions/extension_tts_api_linux.cc
@@ -0,0 +1,58 @@
+// Copyright (c) 2010 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.
+
+#include "chrome/browser/extensions/extension_tts_api.h"
+
+#include "base/singleton.h"
+#include "chrome/browser/chromeos/cros/cros_library.h"
+#include "chrome/browser/chromeos/cros/speech_synthesis_library.h"
+
+namespace util = extension_tts_api_util;
+
+namespace {
+const char kNotSupportedError[] =
+    "Native speech synthesis not supported on this platform.";
+};
+
+class ExtensionTtsPlatformImplLinux : public ExtensionTtsPlatformImpl {
+ public:
+  virtual bool Speak(
+      const std::string& utterance,
+      const std::string& language,
+      const std::string& gender,
+      double rate,
+      double pitch,
+      double volume) {
+    error_ = kNotSupportedError;
+    return false;
+  }
+
+  virtual bool StopSpeaking() {
+    error_ = kNotSupportedError;
+    return false;
+  }
+
+  virtual bool IsSpeaking() {
+    error_ = kNotSupportedError;
+    return false;
+  }
+
+  // Get the single instance of this class.
+  static ExtensionTtsPlatformImplLinux* GetInstance() {
+    return ExtensionTtsPlatformImplLinux::GetInstance();
+  }
+
+ private:
+  ExtensionTtsPlatformImplLinux() {}
+  virtual ~ExtensionTtsPlatformImplLinux() {}
+
+  friend struct DefaultSingletonTraits<ExtensionTtsPlatformImplLinux>;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionTtsPlatformImplLinux);
+};
+
+// static
+ExtensionTtsPlatformImpl* ExtensionTtsPlatformImpl::GetInstance() {
+  return ExtensionTtsPlatformImplLinux::GetInstance();
+}
diff --git a/chrome/browser/extensions/extension_tts_api_mac.mm b/chrome/browser/extensions/extension_tts_api_mac.mm
index 1b45380..2e97aca 100644
--- a/chrome/browser/extensions/extension_tts_api_mac.mm
+++ b/chrome/browser/extensions/extension_tts_api_mac.mm
@@ -6,6 +6,7 @@
 
 #include <string>
 
+#include "base/singleton.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/extension_function.h"
 
@@ -13,57 +14,87 @@
 
 namespace util = extension_tts_api_util;
 
-static NSSpeechSynthesizer* speech_synthesizer_;
+class ExtensionTtsPlatformImplMac : public ExtensionTtsPlatformImpl {
+ public:
+  virtual bool Speak(
+      const std::string& utterance,
+      const std::string& language,
+      const std::string& gender,
+      double rate,
+      double pitch,
+      double volume);
 
-void InitializeSpeechSynthesizer() {
-  if (!speech_synthesizer_)
-    speech_synthesizer_ = [[NSSpeechSynthesizer alloc] init];
+  virtual bool StopSpeaking();
+
+  virtual bool IsSpeaking();
+
+  // Get the single instance of this class.
+  static ExtensionTtsPlatformImplMac* GetInstance();
+
+ private:
+  ExtensionTtsPlatformImplMac();
+  virtual ~ExtensionTtsPlatformImplMac() {}
+
+  NSSpeechSynthesizer* speech_synthesizer_;
+
+  friend struct DefaultSingletonTraits<ExtensionTtsPlatformImplMac>;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionTtsPlatformImplMac);
+};
+
+// static
+ExtensionTtsPlatformImpl* ExtensionTtsPlatformImpl::GetInstance() {
+  return ExtensionTtsPlatformImplMac::GetInstance();
 }
 
-bool ExtensionTtsSpeakFunction::RunImpl() {
-  InitializeSpeechSynthesizer();
-  std::string utterance;
-  EXTENSION_FUNCTION_VALIDATE(args_->GetString(0, &utterance));
-  DictionaryValue* speak_options = NULL;
-
-  // Parse speech properties.
-  if (args_->GetDictionary(1, &speak_options)) {
-    std::string str_value;
-    double real_value;
-    // NSSpeechSynthesizer equivalents for kGenderKey and kLanguageNameKey do
-    // not exist and thus are not supported.
-    if (util::ReadNumberByKey(speak_options, util::kRateKey, &real_value)) {
-      // The TTS api defines rate via words per minute.
-      [speech_synthesizer_
-          setObject:[NSNumber numberWithInt:real_value*400]
-          forProperty:NSSpeechRateProperty error:nil];
-    }
-    if (util::ReadNumberByKey(speak_options, util::kPitchKey, &real_value)) {
-      // The TTS api allows an approximate range of 30 to 65 for speech pitch.
-      [speech_synthesizer_
-          setObject: [NSNumber numberWithInt:(real_value*35 + 30)]
-          forProperty:NSSpeechPitchBaseProperty error:nil];
-    }
-    if (util::ReadNumberByKey(speak_options, util::kVolumeKey, &real_value)) {
-      // The TTS api allows a range of 0.0 to 1.0 for speech volume.
-      [speech_synthesizer_
-          setObject: [NSNumber numberWithFloat:real_value]
-          forProperty:NSSpeechVolumeProperty error:nil];
-    }
+bool ExtensionTtsPlatformImplMac::Speak(
+    const std::string& utterance,
+    const std::string& language,
+    const std::string& gender,
+    double rate,
+    double pitch,
+    double volume) {
+  // NSSpeechSynthesizer equivalents for kGenderKey and kLanguageNameKey do
+  // not exist and thus are not supported.
+
+  if (rate >= 0.0) {
+    // The TTS api defines rate via words per minute.
+    [speech_synthesizer_
+        setObject:[NSNumber numberWithInt:rate * 400]
+        forProperty:NSSpeechRateProperty error:nil];
   }
 
-  return
-      [speech_synthesizer_ startSpeakingString:
-           [NSString stringWithUTF8String: utterance.c_str()]];
+  if (pitch >= 0.0) {
+    // The TTS api allows an approximate range of 30 to 65 for speech pitch.
+    [speech_synthesizer_
+        setObject: [NSNumber numberWithInt:(pitch * 35 + 30)]
+        forProperty:NSSpeechPitchBaseProperty error:nil];
+  }
+
+  if (volume >= 0.0) {
+    [speech_synthesizer_
+        setObject: [NSNumber numberWithFloat:volume]
+        forProperty:NSSpeechVolumeProperty error:nil];
+  }
+
+  return [speech_synthesizer_ startSpeakingString:
+             [NSString stringWithUTF8String: utterance.c_str()]];
 }
 
-bool ExtensionTtsStopSpeakingFunction::RunImpl() {
-    InitializeSpeechSynthesizer();
+bool ExtensionTtsPlatformImplMac::StopSpeaking() {
   [speech_synthesizer_ stopSpeaking];
   return true;
 }
 
-bool ExtensionTtsIsSpeakingFunction::RunImpl() {
-    InitializeSpeechSynthesizer();
+bool ExtensionTtsPlatformImplMac::IsSpeaking() {
   return [speech_synthesizer_ isSpeaking];
 }
+
+ExtensionTtsPlatformImplMac::ExtensionTtsPlatformImplMac() {
+  speech_synthesizer_ = [[NSSpeechSynthesizer alloc] init];
+}
+
+// static
+ExtensionTtsPlatformImplMac* ExtensionTtsPlatformImplMac::GetInstance() {
+  return Singleton<ExtensionTtsPlatformImplMac>::get();
+}
diff --git a/chrome/browser/extensions/extension_tts_api_win.cc b/chrome/browser/extensions/extension_tts_api_win.cc
index 480880b..a9a6062 100644
--- a/chrome/browser/extensions/extension_tts_api_win.cc
+++ b/chrome/browser/extensions/extension_tts_api_win.cc
@@ -11,113 +11,112 @@
 #include "base/scoped_comptr_win.h"
 #include "base/singleton.h"
 #include "base/string_number_conversions.h"
+#include "base/utf_string_conversions.h"
 #include "base/values.h"
 
 namespace util = extension_tts_api_util;
 
-class SpeechSynthesizerWrapper {
+class ExtensionTtsPlatformImplWin : public ExtensionTtsPlatformImpl {
  public:
-  SpeechSynthesizerWrapper() : speech_synthesizer_(NULL),
-                               paused_(false),
-                               permanent_failure_(false) {
-    InitializeSpeechSynthesizer();
-  }
+  virtual bool Speak(
+      const std::string& utterance,
+      const std::string& language,
+      const std::string& gender,
+      double rate,
+      double pitch,
+      double volume);
 
-  bool InitializeSpeechSynthesizer() {
-    if (!SUCCEEDED(CoCreateInstance(CLSID_SpVoice,
-                                    NULL,
-                                    CLSCTX_SERVER,
-                                    IID_ISpVoice,
-                                    reinterpret_cast<void**>(
-                                        &speech_synthesizer_)))) {
-      permanent_failure_ = true;
-      return false;
-    }
-
-    if (paused_)
-      speech_synthesizer_->Resume();
-    return true;
-  }
+  virtual bool StopSpeaking();
 
-  ScopedComPtr<ISpVoice> speech_synthesizer() {
-    return speech_synthesizer_;
-  }
+  virtual bool IsSpeaking();
 
-  bool paused() {
-    return paused_;
-  }
-
-  void paused(bool state) {
-    paused_ = state;
-  }
+  // Get the single instance of this class.
+  static ExtensionTtsPlatformImplWin* GetInstance();
 
  private:
+  ExtensionTtsPlatformImplWin();
+  virtual ~ExtensionTtsPlatformImplWin() {}
+
   ScopedComPtr<ISpVoice> speech_synthesizer_;
   bool paused_;
-  // Indicates an error retrieving the SAPI COM interface.
-  bool permanent_failure_;
+
+  friend struct DefaultSingletonTraits<ExtensionTtsPlatformImplWin>;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionTtsPlatformImplWin);
 };
 
-typedef Singleton<SpeechSynthesizerWrapper> SpeechSynthesizerSingleton;
-
-bool ExtensionTtsSpeakFunction::RunImpl() {
-  ScopedComPtr<ISpVoice> speech_synthesizer =
-      SpeechSynthesizerSingleton::get()->speech_synthesizer();
-  if (speech_synthesizer) {
-    std::wstring utterance;
-    EXTENSION_FUNCTION_VALIDATE(args_->GetString(0, &utterance));
-
-    std::string options = "";
-    DictionaryValue* speak_options = NULL;
-
-    // Parse speech properties.
-    if (args_->GetDictionary(1, &speak_options)) {
-      std::string str_value;
-      double real_value;
-      // Speech API equivalents for kGenderKey and kLanguageNameKey do not
-      // exist and thus are not supported.
-      if (util::ReadNumberByKey(speak_options, util::kRateKey, &real_value)) {
-        // The TTS api allows a range of -10 to 10 for speech rate.
-        speech_synthesizer->SetRate(static_cast<int32>(real_value*20 - 10));
-      }
-      if (util::ReadNumberByKey(speak_options, util::kPitchKey, &real_value)) {
-        // The TTS api allows a range of -10 to 10 for speech pitch.
-        // TODO(dtseng): cleanup if we ever
-        // use any other properties that require xml.
-        std::wstring pitch_value =
-            base::IntToString16(static_cast<int>(real_value*20 - 10));
-        utterance = L"<pitch absmiddle=\"" + pitch_value + L"\">" +
-            utterance + L"</pitch>";
-      }
-      if (util::ReadNumberByKey(
-          speak_options, util::kVolumeKey, &real_value)) {
-        // The TTS api allows a range of 0 to 100 for speech volume.
-        speech_synthesizer->SetVolume(static_cast<uint16>(real_value * 100));
-      }
-    }
-
-    if (SpeechSynthesizerSingleton::get()->paused())
-      speech_synthesizer->Resume();
-    speech_synthesizer->Speak(
-        utterance.c_str(), SPF_ASYNC | SPF_PURGEBEFORESPEAK, NULL);
-    return true;
+// static
+ExtensionTtsPlatformImpl* ExtensionTtsPlatformImpl::GetInstance() {
+  return ExtensionTtsPlatformImplWin::GetInstance();
+}
+
+bool ExtensionTtsPlatformImplWin::Speak(
+    const std::string& src_utterance,
+    const std::string& language,
+    const std::string& gender,
+    double rate,
+    double pitch,
+    double volume) {
+  std::wstring utterance = UTF8ToUTF16(src_utterance);
+
+  if (!speech_synthesizer_)
+    return false;
+
+  // Speech API equivalents for kGenderKey and kLanguageNameKey do not
+  // exist and thus are not supported.
+
+  if (rate >= 0.0) {
+    // The TTS api allows a range of -10 to 10 for speech rate.
+    speech_synthesizer_->SetRate(static_cast<int32>(rate * 20 - 10));
   }
 
-  return false;
+  if (pitch >= 0.0) {
+    // The TTS api allows a range of -10 to 10 for speech pitch.
+    // TODO(dtseng): cleanup if we ever use any other properties that
+    // require xml.
+    std::wstring pitch_value =
+        base::IntToString16(static_cast<int>(pitch * 20 - 10));
+    utterance = L"<pitch absmiddle=\"" + pitch_value + L"\">" +
+        utterance + L"</pitch>";
+  }
+
+  if (volume >= 0.0) {
+    // The TTS api allows a range of 0 to 100 for speech volume.
+    speech_synthesizer_->SetVolume(static_cast<uint16>(volume * 100));
+  }
+
+  if (paused_)
+    speech_synthesizer_->Resume();
+  speech_synthesizer_->Speak(
+      utterance.c_str(), SPF_ASYNC | SPF_PURGEBEFORESPEAK, NULL);
+
+  return true;
 }
 
-bool ExtensionTtsStopSpeakingFunction::RunImpl() {
-  // We need to keep track of the paused state since SAPI doesn't have a stop
-  // method.
-  ScopedComPtr<ISpVoice> speech_synthesizer =
-      SpeechSynthesizerSingleton::get()->speech_synthesizer();
-  if (speech_synthesizer && !SpeechSynthesizerSingleton::get()->paused()) {
-    speech_synthesizer->Pause();
-    SpeechSynthesizerSingleton::get()->paused(true);
+bool ExtensionTtsPlatformImplWin::StopSpeaking() {
+  if (!speech_synthesizer_ && !paused_) {
+    speech_synthesizer_->Pause();
+    paused_ = true;
   }
   return true;
 }
 
-bool ExtensionTtsIsSpeakingFunction::RunImpl() {
+bool ExtensionTtsPlatformImplWin::IsSpeaking() {
   return false;
 }
+
+ExtensionTtsPlatformImplWin::ExtensionTtsPlatformImplWin()
+  : speech_synthesizer_(NULL),
+    paused_(false) {
+  CoCreateInstance(
+      CLSID_SpVoice,
+      NULL,
+      CLSCTX_SERVER,
+      IID_ISpVoice,
+      reinterpret_cast<void**>(&speech_synthesizer_));
+}
+
+// static
+ExtensionTtsPlatformImplWin* ExtensionTtsPlatformImplWin::GetInstance() {
+  return Singleton<ExtensionTtsPlatformImplWin>::get();
+}
diff --git a/chrome/browser/extensions/extension_tts_apitest.cc b/chrome/browser/extensions/extension_tts_apitest.cc
index 5acda10..dcdfb9d5 100644
--- a/chrome/browser/extensions/extension_tts_apitest.cc
+++ b/chrome/browser/extensions/extension_tts_apitest.cc
@@ -22,5 +22,5 @@ IN_PROC_BROWSER_TEST_F(ExtensionApiTest, MAYBE_Tts) {
   crosMock.InitMockSpeechSynthesisLibrary();
   crosMock.SetSpeechSynthesisLibraryExpectations();
 
-  ASSERT_TRUE(RunExtensionTest("tts")) << message_;
+  ASSERT_TRUE(RunExtensionTest("tts/chromeos")) << message_;
 }
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 59f2055..6ee4855 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1543,7 +1543,8 @@
         'browser/extensions/extension_test_api.h',
         'browser/extensions/extension_tts_api.cc',
         'browser/extensions/extension_tts_api.h',
-        'browser/extensions/extension_tts_api_gtk.cc',
+        'browser/extensions/extension_tts_api_chromeos.cc',
+        'browser/extensions/extension_tts_api_linux.cc',
         'browser/extensions/extension_tts_api_mac.mm',
         'browser/extensions/extension_tts_api_util.cc',
         'browser/extensions/extension_tts_api_util.h',
@@ -3294,7 +3295,7 @@
             ['exclude', 'browser/dom_ui/filebrowse_ui.cc'],
             ['exclude', 'browser/dom_ui/mediaplayer_ui.cc'],
             ['exclude', 'browser/dom_ui/slideshow_ui.cc'],
-            ['exclude', 'browser/extensions/extension_tts_api.cc'],
+            ['exclude', 'browser/extensions/extension_tts_api_chromeos.cc'],
             ['exclude', 'browser/renderer_host/offline_resource_handler.cc'],
             ['exclude', 'browser/renderer_host/offline_resource_handler.h'],
           ],
@@ -3960,13 +3961,11 @@
             # non-ChromeOS views Linux builds.
             ['OS=="linux" and toolkit_views==1 and chromeos==0', {
               'sources/': [
-                ['exclude', '^browser/extensions/extension_tts_api.cc'],
                 ['include', '^browser/gtk/dialogs_gtk.cc'],
                 ['include', '^browser/gtk/external_protocol_dialog_gtk.cc'],
                 ['include', '^browser/gtk/external_protocol_dialog_gtk.h'],
                 ['include', '^browser/views/notifications/balloon_view.cc'],
                 ['include', '^browser/views/notifications/balloon_view.h'],
-
                 ['exclude', '^browser/views/select_file_dialog.cc'],
               ],
             }],
@@ -3983,7 +3982,7 @@
             }],
             ['OS=="linux" and chromeos==1',{
               'sources/': [
-                ['exclude', '^browser/extensions/extension_tts_api_gtk.cc'],
+                ['exclude', '^browser/extensions/extension_tts_api_linux.cc'],
                 ['exclude', '^browser/notifications/balloon_collection.cc'],
                 ['exclude', '^browser/notifications/balloon_collection_impl.h'],
                 ['exclude', '^browser/notifications/balloon_collection_linux.cc'],
diff --git a/chrome/test/data/extensions/api_test/tts/manifest.json b/chrome/test/data/extensions/api_test/tts/chromeos/manifest.json
index a43bc3d..a43bc3d 100644
--- a/chrome/test/data/extensions/api_test/tts/manifest.json
+++ b/chrome/test/data/extensions/api_test/tts/chromeos/manifest.json
diff --git a/chrome/test/data/extensions/api_test/tts/test.html b/chrome/test/data/extensions/api_test/tts/chromeos/test.html
index 46f4d74..46f4d74 100644
--- a/chrome/test/data/extensions/api_test/tts/test.html
+++ b/chrome/test/data/extensions/api_test/tts/chromeos/test.html
diff --git a/chrome/test/data/extensions/api_test/tts/test.js b/chrome/test/data/extensions/api_test/tts/chromeos/test.js
index df5837b..0cf73bc0 100644
--- a/chrome/test/data/extensions/api_test/tts/test.js
+++ b/chrome/test/data/extensions/api_test/tts/chromeos/test.js
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// TTS api test for Chrome. This is currently limited to ChromeOS.
-// browser_tests.exe --gtest_filter=ExtensionApiTest.Tts
+// TTS api test for Chrome on ChromeOS.
+// browser_tests.exe --gtest_filter=ExtensionApiTest.TtsOnChromeOs
 
 chrome.test.runTests([
   function testSpeak() {
@@ -20,12 +20,13 @@ chrome.test.runTests([
   function testIsSpeaking() {
     for (var i = 0; i < 3; i++) {
       chrome.experimental.tts.isSpeaking(function(speaking) {
-            chrome.test.assertTrue(speaking);
-          });
+          chrome.test.assertTrue(speaking);
+        });
     }
     chrome.experimental.tts.isSpeaking(function(speaking) {
-            chrome.test.assertFalse(speaking);
-            chrome.test.succeed();
-          });
+        chrome.test.assertFalse(speaking);
+        chrome.test.succeed();
+      });
   }
-]);
\ No newline at end of file
+
+]);