Return correct minimum size set by a client.

This CL hook up minimum size to
Widget::GetMinimumSize/WindowDelegate::GetMinimumSize.

BUG=b/72402291
TEST=Covered by unit test.

Change-Id: I6977f5578c5f8fd3992917f818e38a713689d84f
Reviewed-on: https://chromium-review.googlesource.com/883402
Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
Reviewed-by: David Reveman <reveman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531780}

components/exo/shell_surface_base.cc

@@ -65,6 +65,29 @@ const struct {
     {ui::VKEY_W, ui::EF_SHIFT_DOWN | ui::EF_CONTROL_DOWN},
     {ui::VKEY_F4, ui::EF_ALT_DOWN}};
 
+class ShellSurfaceWidget : public views::Widget {
+ public:
+  explicit ShellSurfaceWidget(ShellSurfaceBase* shell_surface)
+      : shell_surface_(shell_surface) {}
+
+  // Overridden from views::Widget:
+  void Close() override { shell_surface_->Close(); }
+  void OnKeyEvent(ui::KeyEvent* event) override {
+    // Handle only accelerators. Do not call Widget::OnKeyEvent that eats focus
+    // management keys (like the tab key) as well.
+    if (GetFocusManager()->ProcessAccelerator(ui::Accelerator(*event)))
+      event->SetHandled();
+  }
+  gfx::Size GetMinimumSize() const override {
+    return shell_surface_->GetMinimumSize();
+  }
+
+ private:
+  ShellSurfaceBase* const shell_surface_;
+
+  DISALLOW_COPY_AND_ASSIGN(ShellSurfaceWidget);
+};
+
 class CustomFrameView : public ash::CustomFrameViewAsh {
  public:
   using ShapeRects = std::vector<gfx::Rect>;
@@ -148,6 +171,10 @@ class CustomFrameView : public ash::CustomFrameViewAsh {
     if (enabled())
       return ash::CustomFrameViewAsh::SizeConstraintsChanged();
   }
+  gfx::Size GetMinimumSize() const override {
+    return static_cast<const ShellSurfaceWidget*>(GetWidget())
+        ->GetMinimumSize();
+  }
 
  private:
   // TODO(oshima): Remove this once the transition to new drag/resize
@@ -241,26 +268,6 @@ class CustomWindowTargeter : public aura::WindowTargeter {
   DISALLOW_COPY_AND_ASSIGN(CustomWindowTargeter);
 };
 
-class ShellSurfaceWidget : public views::Widget {
- public:
-  explicit ShellSurfaceWidget(ShellSurfaceBase* shell_surface)
-      : shell_surface_(shell_surface) {}
-
-  // Overridden from views::Widget
-  void Close() override { shell_surface_->Close(); }
-  void OnKeyEvent(ui::KeyEvent* event) override {
-    // Handle only accelerators. Do not call Widget::OnKeyEvent that eats focus
-    // management keys (like the tab key) as well.
-    if (GetFocusManager()->ProcessAccelerator(ui::Accelerator(*event)))
-      event->SetHandled();
-  }
-
- private:
-  ShellSurfaceBase* const shell_surface_;
-
-  DISALLOW_COPY_AND_ASSIGN(ShellSurfaceWidget);
-};
-
 // A place holder to disable default implementation created by
 // ash::CustomFrameViewAsh, which triggers immersive fullscreen etc, which
 // we don't need.

components/exo/shell_surface_unittest.cc

@@ -26,6 +26,7 @@
 #include "components/exo/wm_helper.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/aura/window.h"
+#include "ui/aura/window_delegate.h"
 #include "ui/base/hit_test.h"
 #include "ui/compositor/compositor.h"
 #include "ui/compositor/layer.h"
@@ -312,6 +313,11 @@ TEST_F(ShellSurfaceTest, SetMinimumSize) {
   surface->Attach(buffer.get());
   surface->Commit();
   EXPECT_EQ(size, shell_surface->GetMinimumSize());
+  EXPECT_EQ(size, shell_surface->GetWidget()->GetMinimumSize());
+  EXPECT_EQ(size, shell_surface->GetWidget()
+                      ->GetNativeWindow()
+                      ->delegate()
+                      ->GetMinimumSize());
 }
 
 TEST_F(ShellSurfaceTest, SetMaximumSize) {