Add truncation to StreamCopyOrMoveImpl and test case.

content/browser/fileapi/file_system_operation_impl_unittest.cc

Index: content/browser/fileapi/file_system_operation_impl_unittest.cc
diff --git a/content/browser/fileapi/file_system_operation_impl_unittest.cc b/content/browser/fileapi/file_system_operation_impl_unittest.cc
index afbe664aaf2b3233a9ded3ebfd43aab94a848997..0399fe6ebaa62441dcdea33e11c45dd5bd8b16ee 100644
--- a/content/browser/fileapi/file_system_operation_impl_unittest.cc
+++ b/content/browser/fileapi/file_system_operation_impl_unittest.cc
@@ -50,6 +50,15 @@ void AssertFileErrorEq(const tracked_objects::Location& from_here,
   ASSERT_EQ(expected, actual) << from_here.ToString();
 }
 
+void AssertFileErrorEqWithClosure(
+    const tracked_objects::Location& from_here,
+    base::File::Error expected,
+    base::Closure closure,
+    base::File::Error actual) {
+  ASSERT_EQ(expected, actual) << from_here.ToString();
+  closure.Run();
+}
+
 }  // namespace
 
 // Test class for FileSystemOperationImpl.
@@ -1287,4 +1296,34 @@ TEST_F(FileSystemOperationImplTest,
   EXPECT_EQ(expected_usage, usage);
 }
 
+TEST_F(FileSystemOperationImplTest,
+       TestCopySuccessSrcFileWithDifferentFileSize) {
+  FileSystemURL src_file(CreateFile("src"));
+  FileSystemURL dest_file(CreateFile("dest"));
+
+  {
+    base::RunLoop run_loop;
+    operation_runner()->Truncate(
+        dest_file, 6,
+        base::Bind(&AssertFileErrorEqWithClosure,
+           FROM_HERE,
+           base::File::FILE_OK,
+           run_loop.QuitClosure()));
+    run_loop.Run();
+  }
+
+  {
+    base::RunLoop run_loop;
+    operation_runner()->Copy(
+        src_file, dest_file, FileSystemOperation::OPTION_NONE,
+        FileSystemOperationRunner::CopyProgressCallback(),
+        base::Bind(&AssertFileErrorEqWithClosure,
+                   FROM_HERE,
+                   base::File::FILE_OK,
+                   run_loop.QuitClosure()));
+    run_loop.Run();
+  }
+  EXPECT_EQ(0, GetFileSize("dest"));
+}
+
 }  // namespace content