Support app window draggable areas in mash.

chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc

Index: chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
diff --git a/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc b/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
index 718bbe92d49cb191aff3b2ca46c6d7ab47be8597..97a16cf253535cb2766d0aab785c0f034c8790cb 100644
--- a/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
+++ b/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
@@ -28,6 +28,14 @@
 #include "ui/views/controls/menu/menu_runner.h"
 #include "ui/views/widget/widget.h"
 
+#if defined(MOJO_SHELL_CLIENT)
+#include "components/mus/public/cpp/property_type_converters.h"
+#include "components/mus/public/cpp/window.h"
+#include "components/mus/public/interfaces/window_manager.mojom.h"
+#include "ui/aura/mus/mus_util.h"
+#include "ui/gfx/skia_util.h"
+#endif
+
 using extensions::AppWindow;
 
 namespace {
@@ -140,6 +148,11 @@ void ChromeNativeAppWindowViewsAuraAsh::OnBeforeWidgetInit(
         ash::Shell::GetContainer(ash::Shell::GetPrimaryRootWindow(),

[James Cook, 2016/06/14 23:44:56]

aside: This is going to need to get fixed someday to use
WmRootWindowController::ConfigureWidgetInitParamsForContainer. But today is not
that day.

[msw, 2016/06/15 17:06:40]

Acknowledged.

                                  ash::kShellWindowId_ImeWindowParentContainer);
   }
+#if defined(MOJO_SHELL_CLIENT)
+  init_params->mus_properties
+      [mus::mojom::WindowManager::kRemoveStandardFrame_Property] =
+      mojo::ConvertTo<std::vector<uint8_t>>(init_params->remove_standard_frame);
+#endif
 }
 
 void ChromeNativeAppWindowViewsAuraAsh::OnBeforePanelWidgetInit(
@@ -312,3 +325,27 @@ void ChromeNativeAppWindowViewsAuraAsh::SetFullscreen(int fullscreen_types) {
     ash::Shell::GetInstance()->UpdateShelfVisibility();
   }
 }
+
+void ChromeNativeAppWindowViewsAuraAsh::UpdateDraggableRegions(
+    const std::vector<extensions::DraggableRegion>& regions) {
+  ChromeNativeAppWindowViewsAura::UpdateDraggableRegions(regions);
+
+#if defined(MOJO_SHELL_CLIENT)
+  // Set the NativeAppWindow's draggable region on the mus window.
+  if (widget() && GetMusWindow(widget()->GetNativeWindow())) {
+    // Supply client area insets that encompass all draggable regions.
+    gfx::Insets insets(GetDraggableRegion()->getBounds().bottom(), 0, 0, 0);

[James Cook, 2016/06/14 23:44:56]

Can GetDraggableRegion return null? I think it can in
ShellNativeAppWindow::GetDraggableRegion() and we might resuscitate app_shell
for mus ash.

[msw, 2016/06/15 17:06:41]

Done.

+
+    // Invert the draggable regions to determine the additional client areas.
+    SkRegion inverted_region;
+    inverted_region.setRect(GetDraggableRegion()->getBounds());

[James Cook, 2016/06/14 23:44:56]

optional: Cache GetDraggableRegion result, since you use it 3 times?

[msw, 2016/06/15 17:06:41]

Done.

+    inverted_region.op(*GetDraggableRegion(), SkRegion::kDifference_Op);
+    std::vector<gfx::Rect> additional_client_regions;
+    for (SkRegion::Iterator i(inverted_region); !i.done(); i.next())
+      additional_client_regions.push_back(gfx::SkIRectToRect(i.rect()));
+
+    GetMusWindow(widget()->GetNativeWindow())
+        ->SetClientArea(insets, std::move(additional_client_regions));
+  }
+#endif
+}