Plumb selection bounds as a single unit

Source/web/WebSelection.cpp

Index: Source/web/WebSelection.cpp
diff --git a/Source/web/WebSelection.cpp b/Source/web/WebSelection.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..f7764239049c84a2ea1c8ad5315d3c41f5dc4d48
--- /dev/null
+++ b/Source/web/WebSelection.cpp
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+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+
+#include "public/web/WebSelection.h"
+
+#include "core/editing/SelectionType.h"
+#include "core/layout/compositing/CompositedSelection.h"
+
+namespace blink {
+
+static WebSelectionBound getWebSelectionBound(const CompositedSelection& selection, bool isBase)
+{
+    ASSERT(selection.type != NoSelection);
+    const CompositedSelectionBound& bound = isBase ? selection.base : selection.extent;
+    ASSERT(bound.layer);
+
+    WebSelectionBound::Type type = WebSelectionBound::Caret;
+    if (selection.type == RangeSelection) {
+        if ((isBase && selection.isBaseFirst) || (!isBase && !selection.isBaseFirst))
+            type = bound.isTextDirectionRTL ? WebSelectionBound::SelectionRight : WebSelectionBound::SelectionLeft;
+        else
+            type = bound.isTextDirectionRTL ? WebSelectionBound::SelectionLeft : WebSelectionBound::SelectionRight;
+    }
+
+    WebSelectionBound result(type);
+    result.layerId = bound.layer->platformLayer()->id();
+    result.edgeTopInLayer = roundedIntPoint(bound.edgeTopInLayer);
+    result.edgeBottomInLayer = roundedIntPoint(bound.edgeBottomInLayer);
+    result.isTextDirectionRTL = bound.isTextDirectionRTL;
+    return result;
+}
+
+// SelectionType enums have the same values; enforced in AssertMatchingEnums.cpp.
+WebSelection::WebSelection(const CompositedSelection& selection)
+    : m_selectionType(static_cast<WebSelection::SelectionType>(selection.type))
+    , m_base(getWebSelectionBound(selection, true))
+    , m_extent(getWebSelectionBound(selection, false))
+    , m_isBaseFirst(selection.isBaseFirst)
+    , m_isEditable(selection.isEditable)
+    , m_isEmptyTextFormControl(selection.isEmptyTextFormControl)
+{
+}
+
+WebSelection::WebSelection(const WebSelection& other)
+    : m_selectionType(other.m_selectionType)
+    , m_base(other.m_base)
+    , m_extent(other.m_extent)
+    , m_isBaseFirst(other.m_isBaseFirst)
+    , m_isEditable(other.m_isEditable)
+    , m_isEmptyTextFormControl(other.m_isEmptyTextFormControl)
+{
+}
+
+} // namespace blink