Use a ResizeObserver to determine default font-size for text tracks

third_party/WebKit/Source/core/layout/LayoutTextTrackContainer.cpp

Index: third_party/WebKit/Source/core/layout/LayoutTextTrackContainer.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutTextTrackContainer.cpp b/third_party/WebKit/Source/core/layout/LayoutTextTrackContainer.cpp
deleted file mode 100644
index 065f95a69facaa42da2b0916fedf04f203b70a6b..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/core/layout/LayoutTextTrackContainer.cpp
+++ /dev/null
@@ -1,78 +0,0 @@
-/*
- * Copyright (C) 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
- * Copyright (C) 2012 Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "core/layout/LayoutTextTrackContainer.h"
-
-#include "core/frame/DeprecatedScheduleStyleRecalcDuringLayout.h"
-#include "core/layout/LayoutVideo.h"
-
-namespace blink {
-
-LayoutTextTrackContainer::LayoutTextTrackContainer(Element* element)
-    : LayoutBlockFlow(element), m_fontSize(0) {}
-
-void LayoutTextTrackContainer::layout() {
-  LayoutBlockFlow::layout();
-  if (style()->display() == EDisplay::kNone)
-    return;
-
-  DeprecatedScheduleStyleRecalcDuringLayout marker(
-      node()->document().lifecycle());
-
-  LayoutObject* mediaLayoutObject = parent();
-  if (!mediaLayoutObject || !mediaLayoutObject->isVideo())
-    return;
-  if (updateSizes(toLayoutVideo(*mediaLayoutObject)))
-    toElement(node())->setInlineStyleProperty(
-        CSSPropertyFontSize, m_fontSize, CSSPrimitiveValue::UnitType::Pixels);
-}
-
-bool LayoutTextTrackContainer::updateSizes(
-    const LayoutVideo& videoLayoutObject) {
-  // FIXME: The video size is used to calculate the font size (a workaround
-  // for lack of per-spec vh/vw support) but the whole media element is used
-  // for cue rendering. This is inconsistent. See also the somewhat related
-  // spec bug: https://www.w3.org/Bugs/Public/show_bug.cgi?id=28105
-  LayoutSize videoSize = videoLayoutObject.replacedContentRect().size();
-
-  float smallestDimension =
-      std::min(videoSize.height().toFloat(), videoSize.width().toFloat());
-
-  float fontSize = smallestDimension * 0.05f;
-
-  // Avoid excessive FP precision issue.
-  // C11 5.2.4.2.2:9 requires assignment and cast to remove extra precision, but
-  // the behavior is currently not portable. fontSize may have precision higher
-  // than m_fontSize thus straight comparison can fail despite they cast to the
-  // same float value.
-  volatile float& currentFontSize = m_fontSize;
-  float oldFontSize = currentFontSize;
-  currentFontSize = fontSize;
-  return currentFontSize != oldFontSize;
-}
-
-}  // namespace blink