[remoteobjects] Move return statement outside array loop

This change addresses the unreachable code warning by moving
the return statement to the outside of the array parameter
handling loop in JSValueToMojom().
Also adds a check for size in the corresponding browser test.

Bug: 346399, 794320
Change-Id: I1b4d77f395bc68c568c8969c398c1eab625aaa80
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2116648
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#753184}

content/browser/frame_host/render_frame_host_impl_browsertest.cc

@@ -4040,6 +4040,9 @@ class MockInnerObject : public blink::mojom::RemoteObject {
 
 class MockObject : public blink::mojom::RemoteObject {
  public:
+  explicit MockObject(
+      mojo::PendingReceiver<blink::mojom::RemoteObject> receiver)
+      : receiver_(this, std::move(receiver)) {}
   void HasMethod(const std::string& name, HasMethodCallback callback) override {
     bool has_method =
         std::find(kMainObject.methods.begin(), kMainObject.methods.end(),
@@ -4061,6 +4064,9 @@ class MockObject : public blink::mojom::RemoteObject {
       result->value = blink::mojom::RemoteInvocationResultValue::NewNumberValue(
           kMainObject.id);
     } else if (name == "readArray") {
+      EXPECT_EQ(1U, arguments.size());
+      EXPECT_TRUE(arguments[0]->is_array_value());
+      num_elements_received_ = arguments[0]->get_array_value().size();
       result->value =
           blink::mojom::RemoteInvocationResultValue::NewBooleanValue(true);
     } else if (name == "getInnerObject") {
@@ -4069,6 +4075,12 @@ class MockObject : public blink::mojom::RemoteObject {
     }
     std::move(callback).Run(std::move(result));
   }
+
+  int get_num_elements_received() const { return num_elements_received_; }
+
+ private:
+  int num_elements_received_ = 0;
+  mojo::Receiver<blink::mojom::RemoteObject> receiver_;
 };
 
 class MockObjectHost : public blink::mojom::RemoteObjectHost {
@@ -4077,8 +4089,7 @@ class MockObjectHost : public blink::mojom::RemoteObjectHost {
       int32_t object_id,
       mojo::PendingReceiver<blink::mojom::RemoteObject> receiver) override {
     if (object_id == kMainObject.id) {
-      mojo::MakeSelfOwnedReceiver(std::make_unique<MockObject>(),
-                                  std::move(receiver));
+      mock_object_ = std::make_unique<MockObject>(std::move(receiver));
     } else if (object_id == kInnerObject.id) {
       mojo::MakeSelfOwnedReceiver(std::make_unique<MockInnerObject>(),
                                   std::move(receiver));
@@ -4093,8 +4104,11 @@ class MockObjectHost : public blink::mojom::RemoteObjectHost {
     return receiver_.BindNewPipeAndPassRemote();
   }
 
+  MockObject* GetMockObject() const { return mock_object_.get(); }
+
  private:
   mojo::Receiver<blink::mojom::RemoteObjectHost> receiver_{this};
+  std::unique_ptr<MockObject> mock_object_;
 };
 
 class RemoteObjectInjector : public WebContentsObserver {
@@ -4102,6 +4116,8 @@ class RemoteObjectInjector : public WebContentsObserver {
   explicit RemoteObjectInjector(WebContents* web_contents)
       : WebContentsObserver(web_contents) {}
 
+  const MockObjectHost& GetObjectHost() const { return host_; }
+
  private:
   void RenderFrameCreated(RenderFrameHost* render_frame_host) override {
     mojo::Remote<blink::mojom::RemoteObjectGateway> gateway;
@@ -4185,6 +4201,8 @@ IN_PROC_BROWSER_TEST_F(RenderFrameHostImplBrowserTest,
 
   std::string kScript = "testObject.readArray([6, 8, 2]);";
   EXPECT_TRUE(EvalJs(web_contents, kScript).error.empty());
+  EXPECT_EQ(
+      3, injector.GetObjectHost().GetMockObject()->get_num_elements_received());
 }
 
 IN_PROC_BROWSER_TEST_F(RenderFrameHostImplBrowserTest,

third_party/blink/renderer/modules/remote_objects/remote_object.cc

@@ -124,10 +124,10 @@ mojom::blink::RemoteInvocationArgumentPtr JSValueToMojom(
 
         nested_arguments.push_back(std::move(nested_argument));
       }
-
-      return mojom::blink::RemoteInvocationArgument::NewArrayValue(
-          std::move(nested_arguments));
     }
+
+    return mojom::blink::RemoteInvocationArgument::NewArrayValue(
+        std::move(nested_arguments));
   }
 
   return nullptr;