Add support for files to drag interception

Currently, the drag interception API in CDP can only drop
text based things like url lists or html. This patch extends
it to also support dropping files from the file system.

Bug: 1225587
Change-Id: I046f3e337cc10141ae2b33eef37cc3670647b0d5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2983535
Commit-Queue: Jan Scheffler <janscheffler@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#905231}

content/browser/devtools/protocol/input_handler.cc

@@ -342,7 +342,15 @@ DropData ProtocolDragDataToDropData(std::unique_ptr<Input::DragData> data) {
   blink::mojom::DragDataPtr mojo_data =
       blink::mojom::DragData::New(std::move(items), absl::nullopt,
                                   network::mojom::ReferrerPolicy::kDefault);
-  return DragDataToDropData(*mojo_data);
+  DropData drop_data = DragDataToDropData(*mojo_data);
+
+  protocol::Array<protocol::String> default_value;
+  for (const auto& file : *data->GetFiles(&default_value)) {
+    drop_data.filenames.emplace_back(base::FilePath::FromUTF8Unsafe(file),
+                                     base::FilePath());
+  }
+
+  return drop_data;
 }
 
 }  // namespace
@@ -517,11 +525,12 @@ class InputHandler::InputInjector
   DISALLOW_COPY_AND_ASSIGN(InputInjector);
 };
 
-InputHandler::InputHandler()
+InputHandler::InputHandler(bool allow_file_access)
     : DevToolsDomainHandler(Input::Metainfo::domainName),
       host_(nullptr),
       page_scale_factor_(1.0),
-      last_id_(0) {}
+      last_id_(0),
+      allow_file_access_(allow_file_access) {}
 
 InputHandler::~InputHandler() = default;
 
@@ -816,6 +825,11 @@ void InputHandler::DispatchDragEvent(
     std::unique_ptr<Input::DragData> data,
     Maybe<int> modifiers,
     std::unique_ptr<DispatchDragEventCallback> callback) {
+  if (!allow_file_access_ && data->HasFiles()) {
+    callback->sendFailure(Response::InvalidParams("Not allowed"));
+    return;
+  }
+
   RenderWidgetHostImpl* widget_host =
       host_ ? host_->GetRenderWidgetHost() : nullptr;
   if (!widget_host || !widget_host->delegate() ||

content/browser/devtools/protocol/input_handler.h

@@ -35,7 +35,7 @@ namespace protocol {
 
 class InputHandler : public DevToolsDomainHandler, public Input::Backend {
  public:
-  InputHandler();
+  explicit InputHandler(bool allow_file_access);
   ~InputHandler() override;
 
   static std::vector<InputHandler*> ForAgentHost(DevToolsAgentHostImpl* host);
@@ -234,6 +234,7 @@ class InputHandler : public DevToolsDomainHandler, public Input::Backend {
   int last_id_;
   bool ignore_input_events_ = false;
   bool intercept_drags_ = false;
+  const bool allow_file_access_;
   std::set<int> pointer_ids_;
   std::unique_ptr<SyntheticPointerDriver> synthetic_pointer_driver_;
   base::flat_map<int, blink::WebTouchPoint> touch_points_;

content/browser/devtools/render_frame_devtools_agent_host.cc

@@ -301,7 +301,8 @@ bool RenderFrameDevToolsAgentHost::AttachSession(DevToolsSession* session,
   session->AddHandler(std::make_unique<protocol::DOMHandler>(
       session->GetClient()->MayReadLocalFiles()));
   session->AddHandler(std::move(emulation_handler));
-  auto input_handler = std::make_unique<protocol::InputHandler>();
+  auto input_handler = std::make_unique<protocol::InputHandler>(
+      session->GetClient()->MayReadLocalFiles());
   input_handler->OnPageScaleFactorChanged(page_scale_factor_);
   session->AddHandler(std::move(input_handler));
   session->AddHandler(std::make_unique<protocol::InspectorHandler>());

third_party/blink/public/devtools_protocol/browser_protocol.pdl

@@ -3944,6 +3944,8 @@ domain Input
   experimental type DragData extends object
     properties
       array of DragDataItem items
+      # List of filenames that should be included when dropping
+      optional array of string files
       # Bit field representing allowed drag operations. Copy = 1, Link = 2, Move = 16
       integer dragOperationsMask
 

third_party/blink/web_tests/inspector-protocol/input/dispatchDragEvent-expected.txt

@@ -15,3 +15,6 @@ div innerHTML:
 wrong dragOperationsMask should not drop
 div innerHTML: 
 
+Dropping files
+div innerHTML: path1<br>
+

third_party/blink/web_tests/inspector-protocol/input/dispatchDragEvent.js

@@ -1,15 +1,27 @@
 (async function(testRunner) {
-  var {page, session, dp} = await testRunner.startHTML(`
+  var {page, session, dp} = await testRunner.startHTML(
+      `
     <div contenteditable></div>
-  `, `Tests Input.dispatchDragEvent method.`);
+  `,
+      `Tests Input.dispatchDragEvent method.`);
 
 
   function dumpError(message) {
     if (message.error)
       testRunner.log('Error: ' + message.error.message);
   }
-  await session.evaluate(`document.querySelector('div').addEventListener('dragover', event => {
+  await session.evaluate(`
+  document.querySelector('div').addEventListener('dragover', event => {
     event.dataTransfer.dropEffect = 'copy';
+  });
+
+  document.querySelector('div').addEventListener('drop', event => {
+    for (const item of event.dataTransfer.items) {
+      if (item.kind === 'file') {
+        event.target.innerHTML += item.getAsFile().name + '<br/>';
+        event.preventDefault();
+      }
+    }
   })`);
 
   testRunner.log('\nDropping plain text');
@@ -25,7 +37,6 @@
     baseURL: 'https://example.com',
   });
 
-
   testRunner.log('\nDropping a link to example.com');
   await drop({
     mimeType: 'text/uri-list',
@@ -45,13 +56,17 @@
     data: 'should not see this',
   }, 2);
 
+  testRunner.log('\nDropping files');
+  await drop(null, 1, ['path1']);
+
   testRunner.completeTest();
 
 
-  async function drop(item, dragOperationsMask = 1) {
+  async function drop(item, dragOperationsMask = 1, files = undefined) {
     await session.evaluate(`document.querySelector('div').textContent = ''`);
     const data = {
-      items: [item],
+      items: item ? [item] : [],
+      files,
       dragOperationsMask,
     };
     dumpError(await dp.Input.dispatchDragEvent({