Remove -Wno-return-std-move flag

Bug: 832211
Change-Id: I9dbfdb0c49aa10f6655454e0d9958f869454f31c
Reviewed-on: https://chromium-review.googlesource.com/1025435Reviewed-by: Greg Thompson <grt@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Vadym Doroshenko <dvadym@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553510}

build/config/compiler/BUILD.gn

@@ -1407,9 +1407,6 @@ config("default_warnings") {
         # Ignore warnings about MSVC optimization pragmas.
         # TODO(thakis): Only for no_chromium_code? http://crbug.com/505314
         "-Wno-ignored-pragma-optimize",
-
-        # TODO(thakis): Enable, https://crbug.com/832211
-        "-Wno-return-std-move",
       ]
     } else if (use_xcode_clang) {
       cflags += [

components/password_manager/core/browser/password_reuse_detector.cc

@@ -182,7 +182,7 @@ PasswordReuseDetector::FindFirstSavedPassword(const base::string16& input) {
     return passwords_.end();
 
   // lower_bound returns the first key that is bigger or equal to input.
-  auto it = passwords_.lower_bound(input);
+  passwords_iterator it = passwords_.lower_bound(input);
   if (it != passwords_.end() && it->first == input) {
     // If the key is equal then a saved password is found.
     return it;

components/zucchini/equivalence_map_unittest.cc

@@ -251,7 +251,7 @@ TEST(EquivalenceMapTest, PruneEquivalencesAndSortBySource) {
   auto PruneEquivalencesAndSortBySourceTest =
       [](std::vector<Equivalence>&& equivalences) {
         OffsetMapper::PruneEquivalencesAndSortBySource(&equivalences);
-        return equivalences;
+        return std::move(equivalences);
       };
 
   EXPECT_EQ(std::vector<Equivalence>(),

third_party/blink/renderer/core/imagebitmap/image_bitmap.cc

@@ -255,13 +255,13 @@ scoped_refptr<StaticBitmapImage> GetImageWithAlphaDisposition(
     AlphaDisposition alpha_disposition) {
   DCHECK(alpha_disposition != kDontChangeAlpha);
   if (alpha_disposition == kDontChangeAlpha)
-    return image;
+    return std::move(image);
   SkAlphaType alpha_type = (alpha_disposition == kPremultiplyAlpha)
                                ? kPremul_SkAlphaType
                                : kUnpremul_SkAlphaType;
   sk_sp<SkImage> skia_image = image->PaintImageForCurrentFrame().GetSkImage();
   if (skia_image->alphaType() == alpha_type)
-    return image;
+    return std::move(image);
 
   // Premul/unpremul are performed in gamma-corrected space, using arithmetic
   // that assumes linear space. It is an incorrect implementation that has