IndexedDB: Fixed support for empty blobs.

content/browser/indexed_db/indexed_db_browsertest.cc

Index: content/browser/indexed_db/indexed_db_browsertest.cc
diff --git a/content/browser/indexed_db/indexed_db_browsertest.cc b/content/browser/indexed_db/indexed_db_browsertest.cc
index fbe35bf8499159e328f4c941901382773a70596f..d8a67c0abdba0f811fbbca4ea775d6c52040cef1 100644
--- a/content/browser/indexed_db/indexed_db_browsertest.cc
+++ b/content/browser/indexed_db/indexed_db_browsertest.cc
@@ -150,6 +150,22 @@ class IndexedDBBrowserTest : public ContentBrowserTest {
     return disk_usage_;
   }
 
+  virtual int RequestBlobFileCount() {
+    PostTaskAndReplyWithResult(
+        GetContext()->TaskRunner(), FROM_HERE,
+        base::Bind(&IndexedDBContext::GetOriginBlobFileCount, GetContext(),
+                   GURL("file:///")),
+        base::Bind(&IndexedDBBrowserTest::DidGetBlobFileCount, this));
+    scoped_refptr<base::ThreadTestHelper> helper(
+        new base::ThreadTestHelper(BrowserMainLoop::GetInstance()
+                                       ->indexed_db_thread()
+                                       ->message_loop_proxy()));
+    EXPECT_TRUE(helper->Run());
+    // Wait for DidGetBlobFileCount to be called.
+    base::MessageLoop::current()->RunUntilIdle();
+    return blob_file_count_;
+  }
+
  private:
   static MockBrowserTestIndexedDBClassFactory* GetTestClassFactory() {
     static ::base::LazyInstance<MockBrowserTestIndexedDBClassFactory>::Leaky
@@ -165,7 +181,10 @@ class IndexedDBBrowserTest : public ContentBrowserTest {
     disk_usage_ = bytes;
   }
 
+  virtual void DidGetBlobFileCount(int count) { blob_file_count_ = count; }
+
   int64 disk_usage_;
+  int blob_file_count_ = 0;
 
   DISALLOW_COPY_AND_ASSIGN(IndexedDBBrowserTest);
 };
@@ -405,6 +424,20 @@ IN_PROC_BROWSER_TEST_F(IndexedDBBrowserTest, CanDeleteWhenOverQuotaTest) {
   SimpleTest(GetTestUrl("indexeddb", "delete_over_quota.html"));
 }
 
+IN_PROC_BROWSER_TEST_F(IndexedDBBrowserTest, EmptyBlob) {
+  // First delete all IDB's for the test origin
+  GetContext()->TaskRunner()->PostTask(

[jsbell, 2015/03/03 22:38:07]

Is this actually necessary? Is state persisted across tests?

[cmumford, 2015/03/03 23:01:35]

Yes, it is necessary. Do you think this should be moved to the SetUp method and
done there?

[jsbell, 2015/03/03 23:37:56]

SetUp would probably be better, but involve a new class. Not a big deal.

+      FROM_HERE, base::Bind(&IndexedDBContextImpl::DeleteForOrigin,
+                            GetContext(), GURL("file:///")));
+  int64 original_count = RequestBlobFileCount();
+  EXPECT_EQ(0, original_count);  // Start with no blob files.
+  SimpleTest(GetTestUrl("indexeddb", "empty_blob.html"));
+  int64 new_count = RequestBlobFileCount();
+  // The test creates/writes an empty blob, and file. It then deletes the one
+  // file, so a single file should be left on disk.
+  EXPECT_EQ(1, new_count);

[jsbell, 2015/03/03 23:37:56]

Is this still valid if the Blob is deleted too? (sorry, I'd missed that this
comment references the test behavior)

+}
+
 IN_PROC_BROWSER_TEST_F(IndexedDBBrowserTestWithGCExposed, BlobDidAck) {
   SimpleTest(GetTestUrl("indexeddb", "blob_did_ack.html"));
   // Wait for idle so that the blob ack has time to be received/processed by