Pass the modifier key state to javascript drag&drop events on Desktop…

… Linux

BUG=413839
TEST=DesktopDragDropClientAuraX11ChromeSourceTargetTest.*

Review URL: https://codereview.chromium.org/755873002

Cr-Commit-Position: refs/heads/master@{#306093}

ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.cc

@@ -21,6 +21,7 @@
 #include "ui/base/x/x11_foreign_window_manager.h"
 #include "ui/base/x/x11_util.h"
 #include "ui/events/event.h"
+#include "ui/events/event_utils.h"
 #include "ui/events/platform/platform_event_source.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/screen.h"
@@ -75,6 +76,33 @@ const char* kAtomsToCache[] = {
   NULL
 };
 
+int XGetModifiers() {
+  XDisplay* display = gfx::GetXDisplay();
+
+  XID root, child;
+  int root_x, root_y, win_x, win_y;
+  unsigned int mask;
+  XQueryPointer(display,
+                DefaultRootWindow(display),
+                &root,
+                &child,
+                &root_x,
+                &root_y,
+                &win_x,
+                &win_y,
+                &mask);
+  int modifiers = ui::EF_NONE;
+  if (mask & ShiftMask)
+    modifiers |= ui::EF_SHIFT_DOWN;
+  if (mask & ControlMask)
+    modifiers |= ui::EF_CONTROL_DOWN;
+  if (mask & Mod1Mask)
+    modifiers |= ui::EF_ALT_DOWN;
+  if (mask & Mod4Mask)
+    modifiers |= ui::EF_COMMAND_DOWN;
+  return modifiers;
+}
+
 // The time to wait for the target to respond after the user has released the
 // mouse button before ending the move loop.
 const int kEndMoveLoopTimeoutMs = 1000;
@@ -138,6 +166,8 @@ class DesktopDragDropClientAuraX11::X11DragContext
   // action list.
   int GetDragOperation() const;
 
+  DesktopDragDropClientAuraX11* source_client() { return source_client_; }
+
  private:
   // Masks the X11 atom |xdnd_operation|'s views representation onto
   // |drag_operation|.
@@ -204,24 +234,24 @@ DesktopDragDropClientAuraX11::X11DragContext::X11DragContext(
       drag_drop_client_(NULL),
       waiting_to_handle_position_(false),
       suggested_action_(None) {
-  bool get_types = ((event.data.l[1] & 1) != 0);
+  if (!source_client_) {
+    bool get_types = ((event.data.l[1] & 1) != 0);
 
-  if (get_types) {
-    if (!ui::GetAtomArrayProperty(source_window_,
-                                  "XdndTypeList",
-                                  &unfetched_targets_)) {
-      return;
-    }
-  } else {
-    // data.l[2,3,4] contain the first three types. Unused slots can be None.
-    for (int i = 0; i < 3; ++i) {
-      if (event.data.l[2+i] != None) {
-        unfetched_targets_.push_back(event.data.l[2+i]);
+    if (get_types) {
+      if (!ui::GetAtomArrayProperty(source_window_,
+                                    "XdndTypeList",
+                                    &unfetched_targets_)) {
+        return;
+      }
+    } else {
+      // data.l[2,3,4] contain the first three types. Unused slots can be None.
+      for (int i = 0; i < 3; ++i) {
+        if (event.data.l[2+i] != None) {
+          unfetched_targets_.push_back(event.data.l[2+i]);
+        }
       }
     }
-  }
 
-  if (!source_client_) {
     // The window doesn't have a DesktopDragDropClientAuraX11, that means it's
     // created by some other process. Listen for messages on it.
     ui::PlatformEventSource::GetInstance()->AddPlatformEventDispatcher(this);
@@ -237,7 +267,6 @@ DesktopDragDropClientAuraX11::X11DragContext::X11DragContext(
     // that we can shortcut the X11 server and ask the owning SelectionOwner
     // for the data it's offering.
     fetched_targets_ = source_client_->GetFormatMap();
-    unfetched_targets_.clear();
   }
 
   ReadActions();
@@ -379,6 +408,7 @@ DesktopDragDropClientAuraX11::DesktopDragDropClientAuraX11(
       xdisplay_(xdisplay),
       xwindow_(xwindow),
       atom_cache_(xdisplay_, kAtomsToCache),
+      current_modifier_state_(ui::EF_NONE),
       target_window_(NULL),
       waiting_on_status_(false),
       status_received_since_enter_(false),
@@ -572,6 +602,13 @@ void DesktopDragDropClientAuraX11::OnXdndDrop(
                                 target_window_location_,
                                 target_window_root_location_,
                                 target_current_context_->GetDragOperation());
+      if (target_current_context_->source_client()) {
+        event.set_flags(target_current_context_->source_client()
+                            ->current_modifier_state());
+      } else {
+        event.set_flags(XGetModifiers());
+      }
+
       drag_operation = delegate->OnPerformDrop(event);
     }
 
@@ -695,17 +732,23 @@ void DesktopDragDropClientAuraX11::OnWindowDestroyed(aura::Window* window) {
   target_window_ = NULL;
 }
 
-void DesktopDragDropClientAuraX11::OnMouseMovement(XMotionEvent* event) {
-  gfx::Point screen_point(event->x_root, event->y_root);
+void DesktopDragDropClientAuraX11::OnMouseMovement(
+    const gfx::Point& screen_point,
+    int flags,
+    base::TimeDelta event_time) {
   if (drag_widget_.get()) {
     drag_widget_->SetBounds(
         gfx::Rect(screen_point - drag_widget_offset_,
                   drag_widget_->GetWindowBoundsInScreen().size()));
     drag_widget_->StackAtTop();
   }
 
+  const int kModifiers = ui::EF_SHIFT_DOWN | ui::EF_CONTROL_DOWN |
+                         ui::EF_ALT_DOWN | ui::EF_COMMAND_DOWN;
+  current_modifier_state_ = flags & kModifiers;
+
   repeat_mouse_move_timer_.Stop();
-  ProcessMouseMove(screen_point, event->time);
+  ProcessMouseMove(screen_point, event_time.InMilliseconds());
 }
 
 void DesktopDragDropClientAuraX11::OnMouseReleased() {
@@ -925,6 +968,12 @@ void DesktopDragDropClientAuraX11::DragTranslate(
       location,
       root_location,
       drag_op));
+  if (target_current_context_->source_client()) {
+    (*event)->set_flags(
+        target_current_context_->source_client()->current_modifier_state());
+  } else {
+    (*event)->set_flags(XGetModifiers());
+  }
   if (target_window_changed)
     (*delegate)->OnDragEntered(*event->get());
 }

ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.h

@@ -95,7 +95,9 @@ class VIEWS_EXPORT DesktopDragDropClientAuraX11
   void OnWindowDestroyed(aura::Window* window) override;
 
   // Overridden from X11WholeScreenMoveLoopDelegate:
-  void OnMouseMovement(XMotionEvent* event) override;
+  void OnMouseMovement(const gfx::Point& screen_point,
+                       int flags,
+                       base::TimeDelta event_time) override;
   void OnMouseReleased() override;
   void OnMoveLoopEnded() override;
 
@@ -170,6 +172,12 @@ class VIEWS_EXPORT DesktopDragDropClientAuraX11
   // server.
   ui::SelectionFormatMap GetFormatMap() const;
 
+  // Returns the modifier state for the most recent mouse move. This is done to
+  // bypass an asynchronous roundtrip with the X11 server.
+  int current_modifier_state() const {
+    return current_modifier_state_;
+  }
+
   // Handling XdndPosition can be paused while waiting for more data; this is
   // called either synchronously from OnXdndPosition, or asynchronously after
   // we've received data requested from the other window.
@@ -205,6 +213,9 @@ class VIEWS_EXPORT DesktopDragDropClientAuraX11
   class X11DragContext;
   scoped_ptr<X11DragContext> target_current_context_;
 
+  // The modifier state for the most recent mouse move.
+  int current_modifier_state_;
+
   // The Aura window that is currently under the cursor. We need to manually
   // keep track of this because Windows will only call our drag enter method
   // once when the user enters the associated X Window. But inside that X