ozone-demo: Fix NOTREACHED while destroying buffers and misc warnings

Need to have the GL context current before deleting the buffers. Since
the context was destoryed before the buffers due to declaration ordering
in the class definition, the context was lost before the buffers were
destroyed.

Also rename the overlay array to signify that it is an array.

Fixed presubmit warning to use base::size over arraysize.

BUG=NONE
TEST=Ran ozone_demo and verified no GL errors are seen on console.

Change-Id: I8e8da2918fe7c1f2cb5cf16bcebddfd453b315b3
Reviewed-on: https://chromium-review.googlesource.com/1039988Reviewed-by: Michael Spang <spang@chromium.org>
Commit-Queue: Daniel Nicoara <dnicoara@chromium.org>
Cr-Commit-Position: refs/heads/master@{#555452}

ui/ozone/demo/surfaceless_gl_renderer.cc

@@ -128,6 +128,11 @@ SurfacelessGlRenderer::~SurfacelessGlRenderer() {
   // Need to make current when deleting the framebuffer resources allocated in
   // the buffers.
   context_->MakeCurrent(surface_.get());
+  for (size_t i = 0; i < base::size(buffers_); ++i)
+    buffers_[i].reset();
+
+  for (size_t i = 0; i < base::size(overlay_buffers_); ++i)
+    overlay_buffers_[i].reset();
 }
 
 bool SurfacelessGlRenderer::Initialize() {
@@ -151,7 +156,7 @@ bool SurfacelessGlRenderer::Initialize() {
   else
     primary_plane_rect_ = gfx::Rect(size_);
 
-  for (size_t i = 0; i < arraysize(buffers_); ++i) {
+  for (size_t i = 0; i < base::size(buffers_); ++i) {
     buffers_[i].reset(new BufferWrapper());
     if (!buffers_[i]->Initialize(widget_, primary_plane_rect_.size()))
       return false;
@@ -159,9 +164,10 @@ bool SurfacelessGlRenderer::Initialize() {
 
   if (command_line->HasSwitch("enable-overlay")) {
     gfx::Size overlay_size = gfx::Size(size_.width() / 8, size_.height() / 8);
-    for (size_t i = 0; i < arraysize(overlay_buffer_); ++i) {
-      overlay_buffer_[i].reset(new BufferWrapper());
-      overlay_buffer_[i]->Initialize(gfx::kNullAcceleratedWidget, overlay_size);
+    for (size_t i = 0; i < base::size(overlay_buffers_); ++i) {
+      overlay_buffers_[i].reset(new BufferWrapper());
+      overlay_buffers_[i]->Initialize(gfx::kNullAcceleratedWidget,
+                                      overlay_size);
 
       glViewport(0, 0, overlay_size.width(), overlay_size.height());
       glClearColor(i, 1.0, 0.0, 1.0);
@@ -190,8 +196,8 @@ void SurfacelessGlRenderer::RenderFrame() {
     // We know at least the primary plane can be scanned out.
     overlay_list.back().overlay_handled = true;
   }
-  if (overlay_buffer_[0]) {
-    overlay_rect = gfx::Rect(overlay_buffer_[0]->size());
+  if (overlay_buffers_[0]) {
+    overlay_rect = gfx::Rect(overlay_buffers_[0]->size());
 
     float steps_num = 5.0f;
     float stepped_fraction =
@@ -227,9 +233,9 @@ void SurfacelessGlRenderer::RenderFrame() {
         primary_plane_rect_, gfx::RectF(0, 0, 1, 1), false);
   }
 
-  if (overlay_buffer_[0] && overlay_list.back().overlay_handled) {
+  if (overlay_buffers_[0] && overlay_list.back().overlay_handled) {
     surface_->ScheduleOverlayPlane(1, gfx::OVERLAY_TRANSFORM_NONE,
-                                   overlay_buffer_[back_buffer_]->image(),
+                                   overlay_buffers_[back_buffer_]->image(),
                                    overlay_rect, gfx::RectF(0, 0, 1, 1), false);
   }
 
@@ -243,7 +249,7 @@ void SurfacelessGlRenderer::RenderFrame() {
 void SurfacelessGlRenderer::PostRenderFrameTask(gfx::SwapResult result) {
   switch (result) {
     case gfx::SwapResult::SWAP_NAK_RECREATE_BUFFERS:
-      for (size_t i = 0; i < arraysize(buffers_); ++i) {
+      for (size_t i = 0; i < base::size(buffers_); ++i) {
         buffers_[i].reset(new BufferWrapper());
         if (!buffers_[i]->Initialize(widget_, primary_plane_rect_.size()))
           LOG(FATAL) << "Failed to recreate buffer";

ui/ozone/demo/surfaceless_gl_renderer.h

@@ -56,7 +56,7 @@ class SurfacelessGlRenderer : public RendererBase {
 
   std::unique_ptr<BufferWrapper> buffers_[2];
 
-  std::unique_ptr<BufferWrapper> overlay_buffer_[2];
+  std::unique_ptr<BufferWrapper> overlay_buffers_[2];
   bool disable_primary_plane_ = false;
   gfx::Rect primary_plane_rect_;