Revert "canvas2d: Use correct buffer format for shared images."

This reverts commit 771db245.

Reason for revert: breaks vulkan_content_browsertests on Linux FYI bots

Original change's description:
> canvas2d: Use correct buffer format for shared images.
> 
> R=​sunnyps@chromium.org
> 
> Bug: 980122
> Change-Id: Id45d60eb7cea1682badf1a02cc18dae572f24e32
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1694246
> Auto-Submit: Khushal <khushalsagar@chromium.org>
> Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
> Reviewed-by: Fernando Serboncini <fserb@chromium.org>
> Commit-Queue: Khushal <khushalsagar@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#676521}

TBR=sunnyps@chromium.org,fserb@chromium.org,khushalsagar@chromium.org

Change-Id: I4531a80f01d60bc4beb8e8d4538e7f3779e43c7d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 980122,983538
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1699734Reviewed-by: Saman Sami <samans@chromium.org>
Commit-Queue: Saman Sami <samans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#676879}

third_party/blink/renderer/platform/graphics/canvas_resource.cc

@@ -685,13 +685,14 @@ CanvasResourceSharedImage::CanvasResourceSharedImage(
       is_overlay_candidate_(is_overlay_candidate),
       size_(size),
       is_origin_top_left_(is_origin_top_left),
-      texture_target_(is_overlay_candidate_
-                          ? gpu::GetBufferTextureTarget(
-                                gfx::BufferUsage::SCANOUT,
-                                ColorParams().GetBufferFormat(),
-                                context_provider_wrapper_->ContextProvider()
-                                    ->GetCapabilities())
-                          : GL_TEXTURE_2D),
+      texture_target_(
+          is_overlay_candidate_
+              ? gpu::GetBufferTextureTarget(
+                    gfx::BufferUsage::SCANOUT,
+                    BufferFormat(ColorParams().TransferableResourceFormat()),
+                    context_provider_wrapper_->ContextProvider()
+                        ->GetCapabilities())
+              : GL_TEXTURE_2D),
       owning_thread_id_(Thread::Current()->ThreadId()),
       owning_thread_task_runner_(Thread::Current()->GetTaskRunner()) {
   if (!context_provider_wrapper_)
@@ -708,7 +709,7 @@ CanvasResourceSharedImage::CanvasResourceSharedImage(
     flags |= gpu::SHARED_IMAGE_USAGE_SCANOUT;
 
   auto shared_image_mailbox = shared_image_interface->CreateSharedImage(
-      viz::GetResourceFormat(ColorParams().GetBufferFormat()), gfx::Size(size),
+      ColorParams().TransferableResourceFormat(), gfx::Size(size),
       ColorParams().GetStorageGfxColorSpace(), flags);
 
   // Wait for the mailbox to be ready to be used.