Revert 1675973002 and 1683213002.

third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.h

Index: third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.h
diff --git a/third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.h b/third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.h
index 8f79ce78c1112d4fdd69ca1c4a726e4f87f28656..87a2789becf24be50f74a058344e569300118688 100644
--- a/third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.h
+++ b/third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.h
@@ -167,18 +167,12 @@ public:
     void addNewMailboxCallback(PassOwnPtr<Closure> closure) { m_newMailboxCallback = std::move(closure); }
 
 protected: // For unittests
-    struct PLATFORM_EXPORT SupportedExtensions {
-        SupportedExtensions();
-
-        bool multisample;
-        bool depth24;
-        bool discardFramebuffer;
-    };
-
     DrawingBuffer(
         PassOwnPtr<WebGraphicsContext3D>,
         PassOwnPtr<Extensions3DUtil>,
-        const SupportedExtensions&,
+        bool multisampleExtensionSupported,
+        bool packedDepthStencilExtensionSupported,
+        bool discardFramebufferSupported,
         PreserveDrawingBuffer,
         WebGraphicsContext3D::Attributes requestedAttributes);
 
@@ -304,7 +298,7 @@ private:
     IntSize m_size;
     WebGraphicsContext3D::Attributes m_requestedAttributes;
     bool m_multisampleExtensionSupported;
-    bool m_depth24ExtensionSupported;
+    bool m_packedDepthStencilExtensionSupported;
     bool m_discardFramebufferSupported;
     Platform3DObject m_fbo;
     // DrawingBuffer's output is double-buffered. m_colorBuffer is the back buffer.
@@ -317,10 +311,12 @@ private:
 
     OwnPtr<Closure> m_newMailboxCallback;
 
+    // This is used when we have OES_packed_depth_stencil.
     Platform3DObject m_depthStencilBuffer;
 
-    // This is used when we only request depth and the OES_depth24 extension is available.
+    // These are used when we don't.
     Platform3DObject m_depthBuffer;
+    Platform3DObject m_stencilBuffer;
 
     // For multisampling.
     Platform3DObject m_multisampleFBO;