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 17e8494068c422100ba2844d5735abde6a19ae48..dd013c6911b7838779c23faf949e1d0f20917e01 100644
--- a/third_party/WebKit/Source/modules/indexeddb/IDBObserver.cpp
+++ b/third_party/WebKit/Source/modules/indexeddb/IDBObserver.cpp
@@ -5,8 +5,11 @@
 #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/IDBObserverInit.h"
 
@@ -29,7 +32,28 @@ IDBObserver::~IDBObserver() {}
 
 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());
+}
+
+void IDBObserver::unobserve(IDBDatabase* database, ExceptionState& exceptionState)
+{
+    if (!database->backend()) {
+        exceptionState.throwDOMException(InvalidStateError, IDBDatabase::databaseClosedErrorMessage);
+        return;
+    }
+    database->backend()->unobserve(this);
 }
 
 DEFINE_TRACE(IDBObserver)