Implement WebGL's commit on the main thread

third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp

Index: third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp b/third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp
index 137299ee91d4b4ba89685e00a6a616e0bef09cb3..ee7b81cb9ec4c8a53de49003037482c78142ee26 100644
--- a/third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp
+++ b/third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp
@@ -9,8 +9,11 @@
 #include "cc/quads/render_pass.h"
 #include "cc/quads/shared_quad_state.h"
 #include "cc/quads/solid_color_draw_quad.h"
+#include "cc/quads/texture_draw_quad.h"
+#include "platform/graphics/StaticBitmapImage.h"
 #include "public/platform/InterfaceProvider.h"
 #include "public/platform/Platform.h"
+#include "third_party/khronos/GLES2/gl2.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkXfermode.h"
 #include "ui/gfx/geometry/rect.h"
@@ -27,10 +30,8 @@ OffscreenCanvasFrameDispatcherImpl::OffscreenCanvasFrameDispatcherImpl(uint32_t
     Platform::current()->interfaceProvider()->getInterface(mojo::GetProxy(&m_service));
 }
 
-void OffscreenCanvasFrameDispatcherImpl::dispatchFrame()
+void OffscreenCanvasFrameDispatcherImpl::dispatchFrame(PassRefPtr<StaticBitmapImage> image)

[Justin Novosad, 2016/09/12 13:53:25]

PassRefPtr is old school.  Use RefPtr, and std::move at the call site.

[xidachen, 2016/09/14 01:33:12]

Done.

 {
-    // TODO(563852/xlai): Currently this is just a simple solid-color compositor
-    // frame. We need to update this function to extract the image data from canvas.
     cc::CompositorFrame frame;
     frame.metadata.device_scale_factor = 1.0f;
     frame.delegated_frame_data.reset(new cc::DelegatedFrameData);
@@ -43,9 +44,43 @@ void OffscreenCanvasFrameDispatcherImpl::dispatchFrame()
     cc::SharedQuadState* sqs = pass->CreateAndAppendSharedQuadState();
     sqs->SetAll(gfx::Transform(), bounds.size(), bounds, bounds, false, 1.f, SkXfermode::kSrcOver_Mode, 0);
 
-    cc::SolidColorDrawQuad* quad = pass->CreateAndAppendDrawQuad<cc::SolidColorDrawQuad>();
-    const bool forceAntialiasingOff = false;
-    quad->SetNew(sqs, bounds, bounds, SK_ColorGREEN, forceAntialiasingOff);
+    // TODO(xidachen): for now, we just submit a SolidColor frame to compositor in the 2d case,
+    // we should extract data from image.
+    if (!image) {
+        cc::SolidColorDrawQuad* quad = pass->CreateAndAppendDrawQuad<cc::SolidColorDrawQuad>();
+        const bool forceAntialiasingOff = false;
+        quad->SetNew(sqs, bounds, bounds, SK_ColorGREEN, forceAntialiasingOff);
+    } else { // WebGL
+        DCHECK(image->isTextureBacked());
+        unsigned resourceId = 1u;
+        cc::TransferableResource resource;
+        resource.id = resourceId++;
+        resource.format = cc::ResourceFormat::RGBA_8888;
+        // TODO(crbug.com/645590): filter should respect the image-rendering CSS property of associated canvas element.
+        resource.filter = GL_LINEAR;
+        resource.size = gfx::Size(m_width, m_height);
+        resource.mailbox_holder = gpu::MailboxHolder(image->getMailbox(), image->getSyncToken(), GL_TEXTURE_2D);

[Justin Novosad, 2016/09/12 13:53:25]

Should we call ensureMailbox first?  I think there would be no harm in that and
it would guard against possible future bugs (with 2D canvas).

[xidachen, 2016/09/14 01:33:12]

Done.

+        resource.read_lock_fences_enabled = false;
+        resource.is_software = false;
+        // TODO(xidachen): making this overlay-able.
+        resource.is_overlay_candidate = false;
+        frame.delegated_frame_data->resource_list.push_back(std::move(resource));
+
+        cc::TextureDrawQuad* quad = pass->CreateAndAppendDrawQuad<cc::TextureDrawQuad>();
+        gfx::Size rectSize(m_width, m_height);
+
+        const bool needsBlending = true;
+        // TOOD(xidachen): this should be inherited from WebGL context's creation settings.

[Justin Novosad, 2016/09/12 13:53:25]

crbug?

[xidachen, 2016/09/14 01:33:12]

Done.

+        const bool premultipliedAlpha = true;
+        const gfx::PointF uvTopLeft(0.f, 0.f);
+        const gfx::PointF uvBottomRight(1.f, 1.f);
+        float vertexOpacity[4] = {1.f, 1.f, 1.f, 1.f};
+        const bool yflipped = false;
+        // TODO(xidachen): this should be true when using style "image-rendering: pixelated".
+        const bool nearestNeighbor = false;
+        quad->SetAll(sqs, bounds, bounds, bounds, needsBlending, resource.id, gfx::Size(), premultipliedAlpha,
+            uvTopLeft, uvBottomRight, SK_ColorTRANSPARENT, vertexOpacity, yflipped, nearestNeighbor, false);
+    }
 
     frame.delegated_frame_data->render_pass_list.push_back(std::move(pass));