Remove code for debugging NV12 swap chain creation failure

We got 1 crash dump for NV12 and 3 for YUY2 all of which are due to OOM.
NV12 failures in UMA seem to be from older clients before the fix for
odd dimensions went in.  Filtering UMA to recent versions shows that
there are no NV12 swap chain creation failures.

Also change default swap chain format to NV12 when overlays are enabled
using command line flags.

Bug: 869677
Change-Id: If847f1d0a6121df27445b99e3bcb62290b3ed5df
Reviewed-on: https://chromium-review.googlesource.com/c/1355616Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612465}

gpu/ipc/service/direct_composition_surface_win.cc

@@ -9,8 +9,6 @@
 #include <dxgi1_6.h>
 
 #include "base/containers/circular_deque.h"
-#include "base/debug/alias.h"
-#include "base/debug/dump_without_crashing.h"
 #include "base/feature_list.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/metrics/histogram_macros.h"
@@ -123,12 +121,11 @@ bool g_supports_scaled_overlays = true;
 // Used for workaround limiting overlay size to monitor size.
 gfx::Size g_overlay_monitor_size;
 
-// Overridden when NV12 is supported, and kDirectCompositionPreferNV12Overlays
-// finch feature is enabled. Default value is set to YUY2 so that we use a valid
-// format for swap chains when forced to enable overlay code path but hardware
-// overlays are not supported.
-OverlayFormat g_overlay_format_used = OverlayFormat::kYUY2;
-DXGI_FORMAT g_overlay_dxgi_format_used = DXGI_FORMAT_YUY2;
+// Preferred overlay format set when detecting hardware overlay support during
+// initialization.  Set to NV12 by default so that it's used when enabling
+// overlays using command line flags.
+OverlayFormat g_overlay_format_used = OverlayFormat::kNV12;
+DXGI_FORMAT g_overlay_dxgi_format_used = DXGI_FORMAT_NV12;
 
 // This is the raw support info, which shouldn't depend on field trial state, or
 // command line flags. Ordered by most preferred to least preferred format.
@@ -1219,14 +1216,6 @@ bool DCLayerTree::SwapChainPresenter::ReallocateSwapChain(
     ui::ProtectedVideoType protected_video_type) {
   TRACE_EVENT0("gpu", "DCLayerTree::SwapChainPresenter::ReallocateSwapChain");
 
-  // TODO(sunnyps): Remove after debugging NV12 create swap chain failure.
-  bool swap_chain_resized =
-      swap_chain_ && (swap_chain_size_ != swap_chain_size);
-  bool swap_chain_toggled_yuv =
-      swap_chain_ && (is_yuv_swapchain_ != use_yuv_swap_chain);
-  base::debug::Alias(&swap_chain_resized);
-  base::debug::Alias(&swap_chain_toggled_yuv);
-
   ReleaseSwapChainResources();
 
   DCHECK(!swap_chain_size.IsEmpty());
@@ -1280,14 +1269,8 @@ bool DCLayerTree::SwapChainPresenter::ReallocateSwapChain(
       "GPU.DirectComposition.SwapChainCreationResult.";
   is_yuv_swapchain_ = false;
 
-  // TODO(sunnyps): Remove after debugging NV12 create swap chain failure.
-  HRESULT hr = S_OK;
-  VisualInfo visual_info = visual_info_;
-  base::debug::Alias(&hr);
-  base::debug::Alias(&desc);
-  base::debug::Alias(&visual_info);
   if (use_yuv_swap_chain) {
-    hr = media_factory->CreateSwapChainForCompositionSurfaceHandle(
+    HRESULT hr = media_factory->CreateSwapChainForCompositionSurfaceHandle(
         d3d11_device_.Get(), swap_chain_handle_.Get(), &desc, nullptr,
         swap_chain_.GetAddressOf());
     is_yuv_swapchain_ = SUCCEEDED(hr);
@@ -1296,9 +1279,6 @@ bool DCLayerTree::SwapChainPresenter::ReallocateSwapChain(
                                   OverlayFormatToString(g_overlay_format_used),
                               SUCCEEDED(hr));
     if (FAILED(hr)) {
-      // TODO(sunnyps): Remove after debugging NV12 create swap chain failure.
-      base::debug::DumpWithoutCrashing();
-
       DLOG(ERROR) << "Failed to create "
                   << OverlayFormatToString(g_overlay_format_used)
                   << " swap chain of size " << swap_chain_size.ToString()