IndexedDB: Align exception priorities with Firefox

third_party/WebKit/Source/modules/indexeddb/IDBDatabase.cpp

Index: third_party/WebKit/Source/modules/indexeddb/IDBDatabase.cpp
diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBDatabase.cpp b/third_party/WebKit/Source/modules/indexeddb/IDBDatabase.cpp
index e578787d82ff46aa5858e53922a8c367f9109a8e..2099bbc4e3c1184107a1bade9f3e765fe616d1fe 100644
--- a/third_party/WebKit/Source/modules/indexeddb/IDBDatabase.cpp
+++ b/third_party/WebKit/Source/modules/indexeddb/IDBDatabase.cpp
@@ -187,13 +187,13 @@ IDBObjectStore* IDBDatabase::createObjectStore(const String& name, const IDBKeyP
         return nullptr;
     }
 
-    if (containsObjectStore(name)) {
-        exceptionState.throwDOMException(ConstraintError, "An object store with the specified name already exists.");
+    if (!keyPath.isNull() && !keyPath.isValid()) {
+        exceptionState.throwDOMException(SyntaxError, "The keyPath option is not a valid key path.");
         return nullptr;
     }
 
-    if (!keyPath.isNull() && !keyPath.isValid()) {
-        exceptionState.throwDOMException(SyntaxError, "The keyPath option is not a valid key path.");
+    if (containsObjectStore(name)) {
+        exceptionState.throwDOMException(ConstraintError, "An object store with the specified name already exists.");
         return nullptr;
     }
 
@@ -271,27 +271,24 @@ IDBTransaction* IDBDatabase::transaction(ScriptState* scriptState, const StringO
         ASSERT_NOT_REACHED();
     }
 
-    if (scope.isEmpty()) {
-        exceptionState.throwDOMException(InvalidAccessError, "The storeNames parameter was empty.");
+    if (m_versionChangeTransaction) {
+        exceptionState.throwDOMException(InvalidStateError, "A version change transaction is running.");
         return nullptr;
     }
 
-    WebIDBTransactionMode mode = IDBTransaction::stringToMode(modeString);
-    if (mode != WebIDBTransactionModeReadOnly && mode != WebIDBTransactionModeReadWrite) {
-        exceptionState.throwTypeError("The mode provided ('" + modeString + "') is not one of 'readonly' or 'readwrite'.");
+    if (m_closePending) {
+        exceptionState.throwDOMException(InvalidStateError, "The database connection is closing.");
         return nullptr;
     }
 
-    if (exceptionState.hadException())
-        return nullptr;
-
-    if (m_versionChangeTransaction) {
-        exceptionState.throwDOMException(InvalidStateError, "A version change transaction is running.");
+    if (!m_backend) {
+        exceptionState.throwDOMException(InvalidStateError, IDBDatabase::databaseClosedErrorMessage);
         return nullptr;
     }
 
-    if (m_closePending) {
-        exceptionState.throwDOMException(InvalidStateError, "The database connection is closing.");
+
+    if (scope.isEmpty()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The storeNames parameter was empty.");
         return nullptr;
     }
 
@@ -305,8 +302,9 @@ IDBTransaction* IDBDatabase::transaction(ScriptState* scriptState, const StringO
         objectStoreIds.append(objectStoreId);
     }
 
-    if (!m_backend) {
-        exceptionState.throwDOMException(InvalidStateError, IDBDatabase::databaseClosedErrorMessage);
+    WebIDBTransactionMode mode = IDBTransaction::stringToMode(modeString);
+    if (mode != WebIDBTransactionModeReadOnly && mode != WebIDBTransactionModeReadWrite) {
+        exceptionState.throwTypeError("The mode provided ('" + modeString + "') is not one of 'readonly' or 'readwrite'.");
         return nullptr;
     }