Force buffer re-allocation when the backing display changes

ui/ozone/platform/drm/gpu/drm_surface_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/message_loop/message_loop.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkDevice.h"
 #include "ui/ozone/platform/drm/gpu/crtc_controller.h"
@@ skipping 55 matching lines @@
       kDefaultWidgetHandle, drm_device_manager_.get(), screen_manager_.get()));
   window->Initialize();
   window->OnBoundsChanged(
       gfx::Rect(gfx::Size(kDefaultMode.hdisplay, kDefaultMode.vdisplay)));
   screen_manager_->AddWindow(kDefaultWidgetHandle, window.Pass());
 
   surface_.reset(
       new ui::DrmSurface(screen_manager_->GetWindow(kDefaultWidgetHandle)));
   surface_->ResizeCanvas(
       gfx::Size(kDefaultMode.hdisplay, kDefaultMode.vdisplay));
+
+  // The window has been remapped to a controller. The first swap will cause the
+  // SWAP_NAK_RECREATE_BUFFERS without actually using the buffers.
+  surface_->PresentCanvas(gfx::Rect());
 }
 
 void DrmSurfaceTest::TearDown() {
   surface_.reset();
   scoped_ptr<ui::DrmWindow> window =
       screen_manager_->RemoveWindow(kDefaultWidgetHandle);
   window->Shutdown();
   drm_ = nullptr;
   message_loop_.reset();
 }
 
 TEST_F(DrmSurfaceTest, CheckFBIDOnSwap) {
   surface_->PresentCanvas(gfx::Rect());
   drm_->RunCallbacks();
   // Framebuffer ID 1 is allocated in SetUp for the buffer used to modeset.
-  EXPECT_EQ(3u, drm_->current_framebuffer());
+  EXPECT_EQ(2u, drm_->current_framebuffer());
   surface_->PresentCanvas(gfx::Rect());
   drm_->RunCallbacks();
-  EXPECT_EQ(2u, drm_->current_framebuffer());
+  EXPECT_EQ(3u, drm_->current_framebuffer());
 }
 
 TEST_F(DrmSurfaceTest, CheckSurfaceContents) {
   SkPaint paint;
   paint.setColor(SK_ColorWHITE);
   SkRect rect =
       SkRect::MakeWH(kDefaultMode.hdisplay / 2, kDefaultMode.vdisplay / 2);
   surface_->GetSurface()->getCanvas()->drawRect(rect, paint);
   surface_->PresentCanvas(
       gfx::Rect(0, 0, kDefaultMode.hdisplay / 2, kDefaultMode.vdisplay / 2));
   drm_->RunCallbacks();
 
   SkBitmap image;
   std::vector<skia::RefPtr<SkSurface>> framebuffers;
   for (const auto& buffer : drm_->buffers()) {
     // Skip cursor buffers.
     if (buffer->width() == kDefaultCursorSize &&
         buffer->height() == kDefaultCursorSize)
       continue;
 
     framebuffers.push_back(buffer);
   }
 
-  // Buffer 0 is the modesetting buffer, buffer 1 is the frontbuffer and buffer
-  // 2 is the backbuffer.
+  // Buffer 0 is the modesetting buffer, buffer 2 is the frontbuffer and buffer
+  // 1 is the backbuffer.
   EXPECT_EQ(3u, framebuffers.size());
 
-  image.setInfo(framebuffers[2]->getCanvas()->imageInfo());
-  EXPECT_TRUE(framebuffers[2]->getCanvas()->readPixels(&image, 0, 0));
+  image.setInfo(framebuffers[1]->getCanvas()->imageInfo());
+  EXPECT_TRUE(framebuffers[1]->getCanvas()->readPixels(&image, 0, 0));
 
   EXPECT_EQ(kDefaultMode.hdisplay, image.width());
   EXPECT_EQ(kDefaultMode.vdisplay, image.height());
 
   // Make sure the updates are correctly propagated to the native surface.
   for (int i = 0; i < image.height(); ++i) {
     for (int j = 0; j < image.width(); ++j) {
       if (j < kDefaultMode.hdisplay / 2 && i < kDefaultMode.vdisplay / 2)
         EXPECT_EQ(SK_ColorWHITE, image.getColor(j, i));
       else
@@ skipping 26 matching lines @@
   std::vector<skia::RefPtr<SkSurface>> framebuffers;
   for (const auto& buffer : drm_->buffers()) {
     // Skip cursor buffers.
     if (buffer->width() == kDefaultCursorSize &&
         buffer->height() == kDefaultCursorSize)
       continue;
 
     framebuffers.push_back(buffer);
   }
 
-  // Buffer 0 is the modesetting buffer, buffer 1 is the backbuffer and buffer
-  // 2 is the frontbuffer.
+  // Buffer 0 is the modesetting buffer, buffer 2 is the backbuffer and buffer
+  // 1 is the frontbuffer.
   EXPECT_EQ(3u, framebuffers.size());
 
-  image.setInfo(framebuffers[1]->getCanvas()->imageInfo());
-  EXPECT_TRUE(framebuffers[1]->getCanvas()->readPixels(&image, 0, 0));
+  image.setInfo(framebuffers[2]->getCanvas()->imageInfo());
+  EXPECT_TRUE(framebuffers[2]->getCanvas()->readPixels(&image, 0, 0));
 
   EXPECT_EQ(kDefaultMode.hdisplay, image.width());
   EXPECT_EQ(kDefaultMode.vdisplay, image.height());
 
   // Make sure the updates are correctly propagated to the native surface.
   for (int i = 0; i < image.height(); ++i) {
     for (int j = 0; j < image.width(); ++j) {
       if (j < kDefaultMode.hdisplay / 2 && i < kDefaultMode.vdisplay / 2)
         EXPECT_EQ(SK_ColorWHITE, image.getColor(j, i));
       else if (j < kDefaultMode.hdisplay / 2)
         EXPECT_EQ(SK_ColorRED, image.getColor(j, i));
       else
         EXPECT_EQ(SK_ColorBLACK, image.getColor(j, i));
     }
   }
 }