Improve core/css exception messages.

Source/core/css/CSSMatrix.cpp

Index: Source/core/css/CSSMatrix.cpp
diff --git a/Source/core/css/CSSMatrix.cpp b/Source/core/css/CSSMatrix.cpp
index 851d7e3f4dd9bec387c19ffbf494d147673f5865..f1138ba55cdb13b35f40f4a88601058e5493467d 100644
--- a/Source/core/css/CSSMatrix.cpp
+++ b/Source/core/css/CSSMatrix.cpp
@@ -70,21 +70,21 @@ void CSSMatrix::setMatrixValue(const String& string, ExceptionState& exceptionSt
         DEFINE_STATIC_REF(RenderStyle, defaultStyle, RenderStyle::createDefaultStyle());
         TransformOperations operations;
         if (!TransformBuilder::createTransformOperations(value.get(), CSSToLengthConversionData(defaultStyle, defaultStyle, 0, 0, 1.0f), operations)) {
-            exceptionState.throwUninformativeAndGenericDOMException(SyntaxError);
+            exceptionState.throwDOMException(SyntaxError, "Failed to interpret '" + string + "' as a transformation operation.");
             return;
         }
 
         // Convert transform operations to a TransformationMatrix. This can fail
         // if a param has a percentage ('%')
         if (operations.dependsOnBoxSize())
-            exceptionState.throwUninformativeAndGenericDOMException(SyntaxError);
+            exceptionState.throwDOMException(SyntaxError, "The transformation depends on the box size, which is not supported.");
         TransformationMatrix t;
         operations.apply(FloatSize(0, 0), t);
 
         // set the matrix
         m_matrix = t;
     } else { // There is something there but parsing failed.
-        exceptionState.throwUninformativeAndGenericDOMException(SyntaxError);
+        exceptionState.throwDOMException(SyntaxError, "Failed to parse '" + string + "'.");
     }
 }
 
@@ -100,7 +100,7 @@ PassRefPtr<CSSMatrix> CSSMatrix::multiply(CSSMatrix* secondMatrix) const
 PassRefPtr<CSSMatrix> CSSMatrix::inverse(ExceptionState& exceptionState) const
 {
     if (!m_matrix.isInvertible()) {
-        exceptionState.throwUninformativeAndGenericDOMException(NotSupportedError);
+        exceptionState.throwDOMException(NotSupportedError, "The matrix is not invertable.");
         return 0;
     }