IDBObserver: Lifetime Management: Adding Observer

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

Index: third_party/WebKit/Source/modules/indexeddb/IDBObserver.cpp
diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBObserver.cpp b/third_party/WebKit/Source/modules/indexeddb/IDBObserver.cpp
index 3110a384e6bc5c41b479b2534ac9d77a5ac83f5e..82e8e1eccb0391b90b49a4a8dfcbf68563cbaa06 100644
--- a/third_party/WebKit/Source/modules/indexeddb/IDBObserver.cpp
+++ b/third_party/WebKit/Source/modules/indexeddb/IDBObserver.cpp
@@ -5,12 +5,14 @@
 #include "modules/indexeddb/IDBObserver.h"
 
 #include "bindings/core/v8/ExceptionState.h"
+#include "bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "bindings/modules/v8/ToV8ForModules.h"
 #include "bindings/modules/v8/V8BindingForModules.h"
+#include "core/dom/ExceptionCode.h"
+#include "modules/indexeddb/IDBDatabase.h"
 #include "modules/indexeddb/IDBObserverCallback.h"
 #include "modules/indexeddb/IDBObserverChanges.h"
 #include "modules/indexeddb/IDBObserverInit.h"
-#include <v8.h>
 
 namespace blink {
 
@@ -29,7 +31,19 @@ IDBObserver::IDBObserver(IDBObserverCallback& callback, const IDBObserverInit& o
 
 void IDBObserver::observe(IDBDatabase* database, IDBTransaction* transaction, ExceptionState& exceptionState)
 {
-    // TODO(palakj): Finish implementation.
+    if (transaction->isFinished() || transaction->isFinishing()) {
+        exceptionState.throwDOMException(TransactionInactiveError, IDBDatabase::transactionFinishedErrorMessage);
+        return;
+    }
+    if (!transaction->isActive()) {
+        exceptionState.throwDOMException(TransactionInactiveError, IDBDatabase::transactionInactiveErrorMessage);
+        return;
+    }
+    if (!database->backend()) {
+        exceptionState.throwDOMException(InvalidStateError, IDBDatabase::databaseClosedErrorMessage);
+        return;
+    }
+    database->backend()->observe(this, transaction->id());
 }
 
 DEFINE_TRACE(IDBObserver)