Fix the volume controlling behaviors.

chrome/browser/ui/views/ash/volume_controller_chromeos.cc

Index: chrome/browser/ui/views/ash/volume_controller_chromeos.cc
diff --git a/chrome/browser/ui/views/ash/volume_controller_chromeos.cc b/chrome/browser/ui/views/ash/volume_controller_chromeos.cc
index 1db47d8ca262c64319db171515b8a1a0d6e7b241..c424cf483176ee5751945ae8eced0b502235e4d1 100644
--- a/chrome/browser/ui/views/ash/volume_controller_chromeos.cc
+++ b/chrome/browser/ui/views/ash/volume_controller_chromeos.cc
@@ -14,11 +14,6 @@ namespace {
 // Percent by which the volume should be changed when a volume key is pressed.
 const double kStepPercentage = 4.0;
 
-// Percent to which the volume should be set when the "volume up" key is pressed
-// while we're muted and have the volume set to 0.  See
-// http://crosbug.com/13618.
-const double kVolumePercentOnVolumeUpWhileMuted = 25.0;
-
 }  // namespace
 
 bool VolumeController::HandleVolumeMute(const ui::Accelerator& accelerator) {
@@ -58,8 +53,11 @@ bool VolumeController::HandleVolumeUp(const ui::Accelerator& accelerator) {
   chromeos::AudioHandler* audio_handler = chromeos::AudioHandler::GetInstance();
   if (audio_handler->IsMuted()) {
     audio_handler->SetMuted(false);
-    if (audio_handler->GetVolumePercent() <= 0.1)  // float comparison
-      audio_handler->SetVolumePercent(kVolumePercentOnVolumeUpWhileMuted);
+    // If volume percent is still 0.0 after reset the mute status, it means that
+    // the mute status was done by VolumeDown, so we need to increase
+    // the volume as usual.
+    if (audio_handler->GetVolumePercent() == 0.0)
+      audio_handler->AdjustVolumeByPercent(kStepPercentage);
   } else {
     audio_handler->AdjustVolumeByPercent(kStepPercentage);
   }