Improve media-related exception messages

Source/core/html/HTMLMediaElement.cpp

Index: Source/core/html/HTMLMediaElement.cpp
diff --git a/Source/core/html/HTMLMediaElement.cpp b/Source/core/html/HTMLMediaElement.cpp
index 47d690db9e70f8f430bcf19a962089a60015a0bd..fe5779b36c03cbb95e2cce81c9c0be6ce565d33f 100644
--- a/Source/core/html/HTMLMediaElement.cpp
+++ b/Source/core/html/HTMLMediaElement.cpp
@@ -1847,7 +1847,7 @@ double HTMLMediaElement::currentTime() const
 void HTMLMediaElement::setCurrentTime(double time, ExceptionState& exceptionState)
 {
     if (m_mediaController) {
-        exceptionState.throwDOMException(InvalidStateError, "No media controller is available.");
+        exceptionState.throwDOMException(InvalidStateError, "The element is slaved to a MediaController.");
         return;
     }
     seek(time, exceptionState);
@@ -2066,7 +2066,7 @@ void HTMLMediaElement::setVolume(double vol, ExceptionState& exceptionState)
     WTF_LOG(Media, "HTMLMediaElement::setVolume(%f)", vol);
 
     if (vol < 0.0f || vol > 1.0f) {
-        exceptionState.throwDOMException(IndexSizeError, ExceptionMessages::indexOutsideRange("volume", vol, 0.0, ExceptionMessages::ExclusiveBound, 1.0, ExceptionMessages::ExclusiveBound));
+        exceptionState.throwDOMException(IndexSizeError, ExceptionMessages::indexOutsideRange("volume", vol, 0.0, ExceptionMessages::InclusiveBound, 1.0, ExceptionMessages::InclusiveBound));
         return;
     }