Fix the speech rate and volume on Chrome OS; after switching the

scale of these parameters in the TTS API, the conversion to Chrome OS
values was done incorrectly and this fixes it.

BUG=91883
TEST=manual testing
Review URL: http://codereview.chromium.org/7550049

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@95781 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/extensions/extension_tts_api_chromeos.cc

@@ -88,7 +88,7 @@ bool ExtensionTtsPlatformImplChromeOs::Speak(
   if (params.rate >= 0.0) {
     AppendSpeakOption(
         chromeos::SpeechSynthesisLibrary::kSpeechPropertyRate,
-        DoubleToString(1.5 + params.rate * 2.5),
+        DoubleToString(params.rate),
         &options);
   }
 
@@ -101,10 +101,11 @@ bool ExtensionTtsPlatformImplChromeOs::Speak(
   }
 
   if (params.volume >= 0.0) {
-    // The TTS service allows a range of 0 to 5 for speech volume.
+    // The Chrome OS TTS service allows a range of 0 to 5 for speech volume,
+    // but 5 clips, so map to a range of 0...4.
     AppendSpeakOption(
         chromeos::SpeechSynthesisLibrary::kSpeechPropertyVolume,
-        DoubleToString(params.volume * 5),
+        DoubleToString(params.volume * 4),
         &options);
   }