Use correct origin when creating WebGL DrawingBuffer

Previously shared images did not track the origin of the underlying
image but OOPR Canvas does require this functionality. This CL just
updates an origin placeholder to use the correct origin when creating
shared images for DrawingBuffer.

Bug: 1031055
Change-Id: I01c2e66d3639ced777bc5603dab32bb1fdf8e7f4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2718889
Reviewed-by: Vasiliy Telezhnikov <vasilyt@chromium.org>
Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Commit-Queue: Nathan Zabriskie <nazabris@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#859051}

third_party/blink/renderer/platform/graphics/gpu/drawing_buffer.cc

@@ -1150,9 +1150,12 @@ bool DrawingBuffer::ResizeDefaultFramebuffer(const IntSize& size) {
       premultiplied_alpha_false_mailbox_.SetZero();
       premultiplied_alpha_false_texture_ = 0;
     }
+    GrSurfaceOrigin origin = opengl_flip_y_extension_
+                                 ? kTopLeft_GrSurfaceOrigin
+                                 : kBottomLeft_GrSurfaceOrigin;
     premultiplied_alpha_false_mailbox_ = sii->CreateSharedImage(
         back_color_buffer_->format, static_cast<gfx::Size>(size),
-        storage_color_space_, kTopLeft_GrSurfaceOrigin, kUnpremul_SkAlphaType,
+        storage_color_space_, origin, kUnpremul_SkAlphaType,
         gpu::SHARED_IMAGE_USAGE_GLES2 |
             gpu::SHARED_IMAGE_USAGE_GLES2_FRAMEBUFFER_HINT |
             gpu::SHARED_IMAGE_USAGE_RASTER,
@@ -1655,6 +1658,9 @@ scoped_refptr<DrawingBuffer::ColorBuffer> DrawingBuffer::CreateColorBuffer(
   uint32_t usage = gpu::SHARED_IMAGE_USAGE_GLES2 |
                    gpu::SHARED_IMAGE_USAGE_GLES2_FRAMEBUFFER_HINT |
                    gpu::SHARED_IMAGE_USAGE_DISPLAY;
+  GrSurfaceOrigin origin = opengl_flip_y_extension_
+                               ? kTopLeft_GrSurfaceOrigin
+                               : kBottomLeft_GrSurfaceOrigin;
 
   viz::ResourceFormat format;
   if (allocate_alpha_channel_) {
@@ -1667,8 +1673,7 @@ scoped_refptr<DrawingBuffer::ColorBuffer> DrawingBuffer::CreateColorBuffer(
   if (UsingSwapChain()) {
     gpu::SharedImageInterface::SwapChainMailboxes mailboxes =
         sii->CreateSwapChain(format, static_cast<gfx::Size>(size),
-                             storage_color_space_, kTopLeft_GrSurfaceOrigin,
-                             kPremul_SkAlphaType,
+                             storage_color_space_, origin, kPremul_SkAlphaType,
                              usage | gpu::SHARED_IMAGE_USAGE_SCANOUT);
     back_buffer_mailbox = mailboxes.back_buffer;
     front_buffer_mailbox = mailboxes.front_buffer;
@@ -1698,7 +1703,7 @@ scoped_refptr<DrawingBuffer::ColorBuffer> DrawingBuffer::CreateColorBuffer(
       if (gpu_memory_buffer) {
         back_buffer_mailbox = sii->CreateSharedImage(
             gpu_memory_buffer.get(), gpu_memory_buffer_manager,
-            storage_color_space_, kTopLeft_GrSurfaceOrigin, kPremul_SkAlphaType,
+            storage_color_space_, origin, kPremul_SkAlphaType,
             usage | gpu::SHARED_IMAGE_USAGE_SCANOUT);
       }
     }
@@ -1715,8 +1720,8 @@ scoped_refptr<DrawingBuffer::ColorBuffer> DrawingBuffer::CreateColorBuffer(
         alpha_type = kUnpremul_SkAlphaType;
 
       back_buffer_mailbox = sii->CreateSharedImage(
-          format, static_cast<gfx::Size>(size), storage_color_space_,
-          kTopLeft_GrSurfaceOrigin, alpha_type, usage, gpu::kNullSurfaceHandle);
+          format, static_cast<gfx::Size>(size), storage_color_space_, origin,
+          alpha_type, usage, gpu::kNullSurfaceHandle);
     }
   }