mac: Use IOSurfaces in Canvas2DLayerBridge.

third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.cpp

Index: third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.cpp b/third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.cpp
index bba9e8349ffac1fd7c69953fed21fd245cc181cb..a1cc74de781f625044ecdb65a3a4199f5a54656a 100644
--- a/third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.cpp
+++ b/third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.cpp
@@ -201,6 +201,64 @@ GLenum Canvas2DLayerBridge::getGLFilter()
     return m_filterQuality == kNone_SkFilterQuality ? GL_NEAREST : GL_LINEAR;
 }
 
+bool Canvas2DLayerBridge::prepareIOSurfaceMailboxFromImage(RefPtr<SkImage>& image, WebExternalTextureMailbox* outMailbox)
+{
+    GLuint textureId, imageId;
+    if (!createIOSurfaceBackedTexture(&textureId, &imageId))
+        return false;
+
+    GLuint imageTexture = skia::GrBackendObjectToGrGLTextureInfo(image->getTextureHandle(true))->fID;
+    context()->copyTextureCHROMIUM(imageTexture, textureId, GL_BGRA_EXT, GL_UNSIGNED_BYTE, GL_FALSE, GL_FALSE, GL_FALSE);
+
+    MailboxInfo& info = createMailboxInfo();
+    info.m_mailbox.textureTarget = GC3D_TEXTURE_RECTANGLE_ARB;
+    context()->genMailboxCHROMIUM(info.m_mailbox.name);
+    context()->produceTextureDirectCHROMIUM(textureId, info.m_mailbox.textureTarget, info.m_mailbox.name);
+    info.m_mailbox.allowOverlay = true;
+    info.m_mailbox.nearestNeighbor = getGLFilter();
+
+    const WGC3Duint64 fenceSync = context()->insertFenceSyncCHROMIUM();
+    context()->flush();
+    info.m_mailbox.validSyncToken = context()->genSyncTokenCHROMIUM(fenceSync, info.m_mailbox.syncToken);
+
+    info.m_CHROMIUMImageId = imageId;
+    info.m_textureId = textureId;
+    *outMailbox = info.m_mailbox;
+
+    // Because we are changing the texture binding without going through skia,
+    // we must dirty the context.
+    GrContext* grContext = m_contextProvider->grContext();
+    grContext->resetContext(kTextureBinding_GrGLBackendState);
+
+    return true;
+}
+
+bool Canvas2DLayerBridge::createIOSurfaceBackedTexture(GLuint* outTexture, GLuint* outImageId)
+{
+    WebGraphicsContext3D* webContext = context();
+    GLuint imageId = webContext->createGpuMemoryBufferImageCHROMIUM(m_size.width(), m_size.height(), GL_BGRA_EXT, GC3D_SCANOUT_CHROMIUM);
+    if (!imageId)
+        return false;
+
+    GLuint textureId= webContext->createTexture();
+    if (!textureId) {
+        webContext->destroyImageCHROMIUM(imageId);
+        return false;
+    }
+
+    GLenum target = GC3D_TEXTURE_RECTANGLE_ARB;
+    webContext->bindTexture(target, textureId);
+    webContext->texParameteri(target, GL_TEXTURE_MAG_FILTER, getGLFilter());
+    webContext->texParameteri(target, GL_TEXTURE_MIN_FILTER, getGLFilter());
+    webContext->texParameteri(target, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    webContext->texParameteri(target, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    webContext->bindTexImage2DCHROMIUM(target, imageId);
+
+    *outTexture = textureId;
+    *outImageId = imageId;
+    return true;
+}
+
 Canvas2DLayerBridge::MailboxInfo& Canvas2DLayerBridge::createMailboxInfo()
 {
     MailboxInfo tmp;
@@ -212,11 +270,16 @@ Canvas2DLayerBridge::MailboxInfo& Canvas2DLayerBridge::createMailboxInfo()
 
 bool Canvas2DLayerBridge::prepareMailboxFromImage(RefPtr<SkImage>& image, WebExternalTextureMailbox* outMailbox)
 {
+    GrContext* grContext = m_contextProvider->grContext();
+    if (RuntimeEnabledFeatures::canvas2dImageChromiumEnabled()) {
+        if (grContext && prepareIOSurfaceMailboxFromImage(image, outMailbox))

[Justin Novosad, 2016/03/02 16:33:45]

I think what you want here is:
if (!grContext)
    return true; // For unit tests
if (prepareIOSurfaceMailboxFromImage(image, outMailbox))
    return false;
// Note: if IOSurface backed texture creation failed we fall back to the
non-IOSurface path.

+            return true;
+    }
+
     MailboxInfo& mailboxInfo = createMailboxInfo();
     mailboxInfo.m_mailbox.nearestNeighbor = getGLFilter() == GL_NEAREST;
     mailboxInfo.m_image = image;
 
-    GrContext* grContext = m_contextProvider->grContext();
     if (!grContext)
         return true; // for testing: skip gl stuff when using a mock graphics context.
 
@@ -735,6 +798,27 @@ void Canvas2DLayerBridge::mailboxReleased(const WebExternalTextureMailbox& mailb
                 }
             }
         }
+
+        if (releasedMailboxInfo->m_CHROMIUMImageId) {
+            ASSERT(releasedMailboxInfo->m_textureId);
+            ASSERT(!releasedMailboxInfo->m_image);
+            if (mailbox.validSyncToken) {
+                context()->waitSyncTokenCHROMIUM(mailbox.syncToken);

[Justin Novosad, 2016/03/02 16:33:45]

This synchronisation is probably unnecessary? In the case of the other code
path, the only reason we needed to sync is because the textures got recycled by
skia, so it was important to make sure that the compositor was done consuming it
before throwing the texture into the recycle bin to prevent read/write race
between contexts. In this case you are just deleting the resource in the current
context, which is equivalent to decrementing a ref count.  In theory you
wouldn't even need to wait for mailboxReleased to delete the texture because you
are not even accessing it from the main thread context after prepareMailbox.

+            }
+
+            WebGraphicsContext3D* webContext = context();
+            GLenum target = GC3D_TEXTURE_RECTANGLE_ARB;

[Justin Novosad, 2016/03/02 16:33:45]

Does the extension for this need to be detected?

+            webContext->bindTexture(target, releasedMailboxInfo->m_textureId);
+            webContext->releaseTexImage2DCHROMIUM(target, releasedMailboxInfo->m_CHROMIUMImageId);
+            webContext->destroyImageCHROMIUM(releasedMailboxInfo->m_CHROMIUMImageId);
+            webContext->deleteTexture(releasedMailboxInfo->m_textureId);
+            webContext->bindTexture(target, 0);
+
+            // Because we are changing the texture binding without going through skia,
+            // we must dirty the context.
+            GrContext* grContext = m_contextProvider->grContext();
+            grContext->resetContext(kTextureBinding_GrGLBackendState);
+        }
     }
 
     RefPtr<Canvas2DLayerBridge> selfRef;
@@ -847,6 +931,8 @@ Canvas2DLayerBridge::MailboxInfo::MailboxInfo(const MailboxInfo& other)
     memcpy(&m_mailbox, &other.m_mailbox, sizeof(m_mailbox));
     m_image = other.m_image;
     m_parentLayerBridge = other.m_parentLayerBridge;
+    m_CHROMIUMImageId = other.m_CHROMIUMImageId;
+    m_textureId = other.m_textureId;
 }
 
 void Canvas2DLayerBridge::Logger::reportHibernationEvent(HibernationEvent event)