fxcrt::{Byte,Wide}String missing move-assign operator

This hasn't been a big deal, since no data is copied, but avoids
some ref-count churn in the process.

Change-Id: I53c059284aa6806793c59a0c19b3e0d7fe4191d6
Reviewed-on: https://pdfium-review.googlesource.com/35350
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/core/fxcrt/widestring_unittest.cpp b/core/fxcrt/widestring_unittest.cpp
index 4572305530..b044a81bb0 100644
--- a/core/fxcrt/widestring_unittest.cpp
+++ b/core/fxcrt/widestring_unittest.cpp
@@ -53,6 +53,37 @@ TEST(WideString, ElementAccess) {
 #endif
 }
 
+TEST(WideString, Assign) {
+  {
+    // Copy-assign.
+    WideString string1;
+    EXPECT_EQ(0, string1.ReferenceCountForTesting());
+    {
+      WideString string2(L"abc");
+      EXPECT_EQ(1, string2.ReferenceCountForTesting());
+
+      string1 = string2;
+      EXPECT_EQ(2, string1.ReferenceCountForTesting());
+      EXPECT_EQ(2, string2.ReferenceCountForTesting());
+    }
+    EXPECT_EQ(1, string1.ReferenceCountForTesting());
+  }
+  {
+    // Move-assign.
+    WideString string1;
+    EXPECT_EQ(0, string1.ReferenceCountForTesting());
+    {
+      WideString string2(L"abc");
+      EXPECT_EQ(1, string2.ReferenceCountForTesting());
+
+      string1 = std::move(string2);
+      EXPECT_EQ(1, string1.ReferenceCountForTesting());
+      EXPECT_EQ(0, string2.ReferenceCountForTesting());
+    }
+    EXPECT_EQ(1, string1.ReferenceCountForTesting());
+  }
+}
+
 TEST(WideString, OperatorLT) {
   WideString empty;
   WideString a(L"a");