(reland)WebGL 2: generate appropriate error for different dimensions of images attached to fbo

third_party/WebKit/Source/modules/webgl/WebGLFramebuffer.cpp

Index: third_party/WebKit/Source/modules/webgl/WebGLFramebuffer.cpp
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLFramebuffer.cpp b/third_party/WebKit/Source/modules/webgl/WebGLFramebuffer.cpp
index ccd6d8caaf99ad3548c4e5d3c4e10b6760fbda4e..4eeaa89566d14da3876eb791002d6ed9f2555805 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLFramebuffer.cpp
+++ b/third_party/WebKit/Source/modules/webgl/WebGLFramebuffer.cpp
@@ -46,6 +46,7 @@ private:
 
     GLsizei width() const override;
     GLsizei height() const override;
+    GLsizei depth() const override;
     GLenum format() const override;
     GLenum type() const override;
     bool isCubeComplete() const override;
@@ -85,6 +86,11 @@ GLsizei WebGLRenderbufferAttachment::height() const
     return m_renderbuffer->height();
 }
 
+GLsizei WebGLRenderbufferAttachment::depth() const
+{
+    return 1;
+}
+
 GLenum WebGLRenderbufferAttachment::format() const
 {
     GLenum format = m_renderbuffer->internalFormat();
@@ -160,6 +166,7 @@ private:
 
     GLsizei width() const override;
     GLsizei height() const override;
+    GLsizei depth() const override;
     GLenum format() const override;
     GLenum type() const override;
     bool isCubeComplete() const override;
@@ -205,6 +212,11 @@ GLsizei WebGLTextureAttachment::height() const
     return m_texture->getHeight(m_target, m_level);
 }
 
+GLsizei WebGLTextureAttachment::depth() const
+{
+    return m_texture->getDepth(m_target, m_level);
+}
+
 GLenum WebGLTextureAttachment::format() const
 {
     return m_texture->getInternalFormat(m_target, m_level);
@@ -539,7 +551,7 @@ GLenum WebGLFramebuffer::colorBufferFormat() const
 GLenum WebGLFramebuffer::checkStatus(const char** reason) const
 {
     unsigned count = 0;
-    GLsizei width = 0, height = 0;
+    GLsizei width = 0, height = 0, depth = 0;
     WebGLAttachment* depthAttachment = nullptr;
     WebGLAttachment* stencilAttachment = nullptr;
     WebGLAttachment* depthStencilAttachment = nullptr;
@@ -567,15 +579,18 @@ GLenum WebGLFramebuffer::checkStatus(const char** reason) const
             depthStencilAttachment = attachment;
             break;
         }
-        if (!isWebGL2OrHigher) {
-            if (!count) {
-                width = attachment->width();
-                height = attachment->height();
-            } else {
-                if (width != attachment->width() || height != attachment->height()) {
-                    *reason = "attachments do not have the same dimensions";
-                    return GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS;
-                }
+        // Note: In GLES 3, images for a framebuffer need not to have the same dimensions to be framebuffer complete.
+        // However, in Direct3D 11, on top of which OpenGL ES 3 behavior is emulated in Windows, all render targets
+        // must have the same size in all dimensions. In order to have consistent WebGL 2 behaviors across platforms,
+        // we generate FRAMEBUFFER_INCOMPLETE_DIMENSIONS in this situation.
+        if (!count) {
+            width = attachment->width();
+            height = attachment->height();
+            depth = attachment->depth();
+        } else {
+            if (width != attachment->width() || height != attachment->height() || depth != attachment->depth()) {
+                *reason = "attachments do not have the same dimensions";
+                return GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS;
             }
         }
         ++count;