IndexedDB: Log exception messages

LayoutTests/storage/indexeddb/keypath-edges-expected.txt

Index: LayoutTests/storage/indexeddb/keypath-edges-expected.txt
diff --git a/LayoutTests/storage/indexeddb/keypath-edges-expected.txt b/LayoutTests/storage/indexeddb/keypath-edges-expected.txt
index 8f84485077286b2ef5491fecbe35469ec2c09748..11d7b811b763fc07709267221733ebe2efc1c7b4 100644
--- a/LayoutTests/storage/indexeddb/keypath-edges-expected.txt
+++ b/LayoutTests/storage/indexeddb/keypath-edges-expected.txt
@@ -20,18 +20,21 @@ Expecting exception from store.put(null)
 PASS Exception was thrown.
 PASS code is 0
 PASS ename is 'DataError'
+Exception message: Evaluating the object store's key path did not yield a value.
 
 Key path doesn't resolve to a value; should yield null, should throw DATA_ERR
 Expecting exception from store.put({})
 PASS Exception was thrown.
 PASS code is 0
 PASS ename is 'DataError'
+Exception message: Evaluating the object store's key path did not yield a value.
 
 Key path resolves to a value that is invalid key; should yield 'invalid' key, should throw DATA_ERR
 Expecting exception from store.put({foo: null})
 PASS Exception was thrown.
 PASS code is 0
 PASS ename is 'DataError'
+Exception message: Evaluating the object store's key path yielded a value that is not a valid key.
 
 Key path resolves to a value that is valid key; should yield 'string' key, should succeed
 store.put({foo: 'zoo'})
@@ -46,12 +49,14 @@ Expecting exception from store.put(null)
 PASS Exception was thrown.
 PASS code is 0
 PASS ename is 'DataError'
+Exception message: A generated key could not be inserted into the value.
 
 Key path doesn't resolve to a value; should yield null but insertion would fail, so put request should raise exception
 Expecting exception from store.put('string')
 PASS Exception was thrown.
 PASS code is 0
 PASS ename is 'DataError'
+Exception message: A generated key could not be inserted into the value.
 
 Key path doesn't resolve to a value; should yield null, key should be generated, put request should succeed
 store.put({})
@@ -62,6 +67,7 @@ Expecting exception from store.put({foo: null})
 PASS Exception was thrown.
 PASS code is 0
 PASS ename is 'DataError'
+Exception message: Evaluating the object store's key path yielded a value that is not a valid key.
 
 Key path resolves to a value that is valid key; should yield 'string' key, should succeed
 store.put({foo: 'zoo'})