Improve Crypto::getRandomValues exception messages.

Source/modules/crypto/Crypto.cpp

Index: Source/modules/crypto/Crypto.cpp
diff --git a/Source/modules/crypto/Crypto.cpp b/Source/modules/crypto/Crypto.cpp
index 1ad5b2f2106a031c92d08ed0484f69216e4a9e96..4a8a7f7e2bd30c9fb9727e275806a014c6a25fd1 100644
--- a/Source/modules/crypto/Crypto.cpp
+++ b/Source/modules/crypto/Crypto.cpp
@@ -61,12 +61,16 @@ Crypto::Crypto()
 // Note: This implementation must be thread-safe, as it is used by workers.
 void Crypto::getRandomValues(ArrayBufferView* array, ExceptionState& exceptionState)
 {
-    if (!array || !isIntegerArray(array)) {
-        exceptionState.throwUninformativeAndGenericDOMException(TypeMismatchError);
+    if (!array) {
+        exceptionState.throwDOMException(TypeMismatchError, "The provided ArrayBufferView is null.");
+        return;
+    }
+    if (!isIntegerArray(array)) {
+        exceptionState.throwDOMException(TypeMismatchError, String::format("The provided ArrayBufferView is of type '%s', which is not an integer array type.", array->typeName()));
         return;
     }
     if (array->byteLength() > 65536) {
-        exceptionState.throwUninformativeAndGenericDOMException(QuotaExceededError);
+        exceptionState.throwDOMException(QuotaExceededError, String::format("The ArrayBufferView's byte length (%u) exceeds the number of bytes of entropy available via this API (65536).", array->byteLength()));
         return;
     }
     cryptographicallyRandomValues(array->baseAddress(), array->byteLength());