Expose APIs for text track settings

Source/core/html/track/vtt/VTTCue.cpp

Index: Source/core/html/track/vtt/VTTCue.cpp
diff --git a/Source/core/html/track/vtt/VTTCue.cpp b/Source/core/html/track/vtt/VTTCue.cpp
index 9276b20b40a82ab615f0b251f8b9c73b5a446b1d..4a533b0a47cb09b5cbb8b179e07dd6d933bb6152 100644
--- a/Source/core/html/track/vtt/VTTCue.cpp
+++ b/Source/core/html/track/vtt/VTTCue.cpp
@@ -38,6 +38,7 @@
 #include "core/dom/DocumentFragment.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/events/Event.h"
+#include "core/frame/Settings.h"
 #include "core/frame/UseCounter.h"
 #include "core/html/HTMLDivElement.h"
 #include "core/html/track/TextTrack.h"
@@ -136,6 +137,14 @@ static bool isInvalidPercentage(double value, ExceptionState& exceptionState)
     return false;
 }
 
+// Sets inline CSS properties on passed in element if value is not an empty string
+static void setInlineStylePropertyIfNotEmpty(Element& element,
+    CSSPropertyID propertyID, const String& value)
+{
+    if (!value.isEmpty())
+        element.setInlineStyleProperty(propertyID, value);
+}
+
 VTTCueBox::VTTCueBox(Document& document, VTTCue* cue)
     : HTMLDivElement(document)
     , m_cue(cue)
@@ -797,8 +806,13 @@ PassRefPtrWillBeRawPtr<VTTCueBox> VTTCue::getDisplayTree()
 
     ASSERT(m_displayTree->firstChild() == m_cueBackgroundBox);
 
-    if (!m_displayTreeShouldChange)
+    if (!m_displayTreeShouldChange) {
+        // Apply updated user style overrides for text tracks when display tree doesn't change.
+        // This ensures that the track settings are refreshed when the video is
+        // replayed or when the user slides back to an already rendered track.
+        applyUserOverrideCSSProperties();
         return m_displayTree;
+    }
 
     createVTTNodeTree();
 
@@ -808,6 +822,9 @@ PassRefPtrWillBeRawPtr<VTTCueBox> VTTCue::getDisplayTree()
     VTTDisplayParameters displayParameters = calculateDisplayParameters();
     m_displayTree->applyCSSProperties(displayParameters);
 
+    // Apply user override settings for text tracks
+    applyUserOverrideCSSProperties();
+
     m_displayTreeShouldChange = false;
 
     return m_displayTree;
@@ -1080,6 +1097,28 @@ void VTTCue::parseSettings(const String& inputString)
         m_regionId = emptyString();
 }
 
+void VTTCue::applyUserOverrideCSSProperties()
+{
+    Settings* settings = document().settings();
+    if (!settings)
+        return;
+
+    setInlineStylePropertyIfNotEmpty(*m_cueBackgroundBox,
+        CSSPropertyBackgroundColor, settings->textTrackBackgroundColor());
+    setInlineStylePropertyIfNotEmpty(*m_cueBackgroundBox,
+        CSSPropertyFontFamily, settings->textTrackFontFamily());
+    setInlineStylePropertyIfNotEmpty(*m_cueBackgroundBox,
+        CSSPropertyFontStyle, settings->textTrackFontStyle());
+    setInlineStylePropertyIfNotEmpty(*m_cueBackgroundBox,
+        CSSPropertyFontVariant, settings->textTrackFontVariant());
+    setInlineStylePropertyIfNotEmpty(*m_cueBackgroundBox,
+        CSSPropertyColor, settings->textTrackTextColor());
+    setInlineStylePropertyIfNotEmpty(*m_cueBackgroundBox,
+        CSSPropertyTextShadow, settings->textTrackTextShadow());
+    setInlineStylePropertyIfNotEmpty(*m_cueBackgroundBox,
+        CSSPropertyFontSize, settings->textTrackTextSize());
+}
+
 ExecutionContext* VTTCue::executionContext() const
 {
     ASSERT(m_cueBackgroundBox);