mash: Fix ui_devtools overlay layer and element coordinates

Use display root windows (not client roots) for highlighting on Chrome OS.
Store the screen offset for the layer used for highlighting.
Store the pinned and hovered item bounds in screen coordinates.
Convert the screen space rects to layer space when painting.

These changes fix ui_devtools highlights for SingleProcessMash.
They also add partial support for highlighting between roots/displays.
(we still only paint to one layer, but should paint to all root/display layers)

Bug: 896977
Test: ui_devtools highlights work better on SingleProcessMash and desktop.
Change-Id: Ib7cefcad5bd890ac81628c5fd717f7fb42da3f4c
Reviewed-on: https://chromium-review.googlesource.com/c/1366787
Commit-Queue: Michael Wasserman <msw@chromium.org>
Reviewed-by: Leonard Grey <lgrey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614844}

components/ui_devtools/views/overlay_agent_aura.cc

@@ -11,11 +11,13 @@
 #include "components/ui_devtools/views/window_element.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/effects/SkDashPathEffect.h"
-#include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/env.h"
 #include "ui/compositor/paint_recorder.h"
+#include "ui/display/display.h"
+#include "ui/display/screen.h"
 #include "ui/events/event.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/geometry/rect_conversions.h"
 #include "ui/gfx/render_text.h"
 #include "ui/views/background.h"
 #include "ui/views/border.h"
@@ -530,20 +532,26 @@ bool OverlayAgentAura::UpdateHighlight(
   }
 
   gfx::NativeWindow root = window_and_bounds.first->GetRootWindow();
+#if defined(OS_CHROMEOS)
+  // Get the screen's display-root window; otherwise, if the window belongs to
+  // a window service client, |root| will only be a client-root window.
+  aura::Window* window = display::Screen::GetScreen()->GetWindowAtScreenPoint(
+      root->GetBoundsInScreen().origin());
+  if (window)  // May be null in unit tests.
+    root = window->GetRootWindow();
+#endif  // OS_CHROMEOS
+
   layer_for_highlighting_->SetBounds(root->bounds());
   layer_for_highlighting_->SchedulePaint(root->bounds());
+  layer_for_highlighting_screen_offset_ =
+      root->GetBoundsInScreen().OffsetFromOrigin();
 
   if (root->layer() != layer_for_highlighting_->parent())
     root->layer()->Add(layer_for_highlighting_.get());
   else
     root->layer()->StackAtTop(layer_for_highlighting_.get());
 
-  aura::client::ScreenPositionClient* screen_position_client =
-      aura::client::GetScreenPositionClient(root);
   hovered_rect_ = window_and_bounds.second;
-  gfx::Point origin = hovered_rect_.origin();
-  screen_position_client->ConvertPointFromScreen(root, &origin);
-  hovered_rect_.set_origin(origin);
   return true;
 }
 
@@ -624,7 +632,9 @@ void OverlayAgentAura::OnPaintLayer(const ui::PaintContext& context) {
   const gfx::Rect& screen_bounds(layer_for_highlighting_->bounds());
   ui::PaintRecorder recorder(context, screen_bounds.size());
   gfx::Canvas* canvas = recorder.canvas();
+  // Convert the hovered rect from screen coordinates to layer coordinates.
   gfx::RectF hovered_rect_f(hovered_rect_);
+  hovered_rect_f.Offset(-layer_for_highlighting_screen_offset_);
 
   cc::PaintFlags flags;
   flags.setStrokeWidth(1.0f);
@@ -648,15 +658,17 @@ void OverlayAgentAura::OnPaintLayer(const ui::PaintContext& context) {
 
     // Display size of the rectangle after mouse click.
     if (show_size_on_canvas_) {
-      DrawSizeOfRectangle(hovered_rect_, RectSide::BOTTOM_SIDE, canvas,
-                          render_text_.get());
+      DrawSizeOfRectangle(gfx::ToNearestRect(hovered_rect_f),
+                          RectSide::BOTTOM_SIDE, canvas, render_text_.get());
     }
     return;
   }
   flags.setPathEffect(nullptr);
   flags.setColor(SK_ColorBLUE);
 
+  // Convert the pinned rect from screen coordinates to layer coordinates.
   gfx::RectF pinned_rect_f(pinned_rect_);
+  pinned_rect_f.Offset(-layer_for_highlighting_screen_offset_);
 
   // Draw |pinned_rect_f| bounds in blue.
   canvas->DrawRect(pinned_rect_f, flags);
@@ -670,9 +682,9 @@ void OverlayAgentAura::OnPaintLayer(const ui::PaintContext& context) {
   flags.setColor(SK_ColorRED);
 
   // Make sure |pinned_rect_f| stays on the right or below of |hovered_rect_f|.
-  if (pinned_rect_.x() < hovered_rect_.x() ||
-      (pinned_rect_.x() == hovered_rect_.x() &&
-       pinned_rect_.y() < hovered_rect_.y())) {
+  if (pinned_rect_f.x() < hovered_rect_f.x() ||
+      (pinned_rect_f.x() == hovered_rect_f.x() &&
+       pinned_rect_f.y() < hovered_rect_f.y())) {
     std::swap(pinned_rect_f, hovered_rect_f);
   }
 

components/ui_devtools/views/overlay_agent_aura.h

@@ -108,9 +108,14 @@ class OverlayAgentAura : public OverlayAgent,
   HighlightRectsConfiguration highlight_rect_config_;
   bool is_swap_ = false;
 
+  // The layer used to paint highlights, and its offset from the screen origin.
   std::unique_ptr<ui::Layer> layer_for_highlighting_;
+  gfx::Vector2d layer_for_highlighting_screen_offset_;
+
+  // Hovered and pinned element bounds in screen coordinates; empty if none.
   gfx::Rect hovered_rect_;
   gfx::Rect pinned_rect_;
+
   int pinned_id_ = 0;
 
   DISALLOW_COPY_AND_ASSIGN(OverlayAgentAura);