Merge WebKit r153448 (Optimizes the number of updateTextTrackDisplay calls)

Source/core/html/HTMLMediaElement.h

Index: Source/core/html/HTMLMediaElement.h
diff --git a/Source/core/html/HTMLMediaElement.h b/Source/core/html/HTMLMediaElement.h
index bbc957d457358843a8510fca927c4d51c2958311..46cafe8d399d4201915a670bfdbb78abce5f2aa4 100644
--- a/Source/core/html/HTMLMediaElement.h
+++ b/Source/core/html/HTMLMediaElement.h
@@ -232,7 +232,11 @@ public:
     void configureTextTrackGroup(const TrackGroup&);
 
     bool textTracksAreReady() const;
-    void configureTextTrackDisplay();
+    enum ConfigureTextTrackDisplayFlags {
+        DoNotAssumeVisibleTextTracksChanged,

[acolwell GONE FROM CHROMIUM, 2013/08/12 20:19:02]

nit: Flags doesn't seem appropriate here since the 2 values are mutually
exclusive. How about something like VisibilityChangeAssumption & change the
values to "AssumeNoVisibleChange" & "AssumeVisibleChange"

[vcarbune.chromium, 2013/08/19 22:20:12]

Done. Minimally, this could have been a boolean parameter, but I think this enum
aids readability.

+        AssumeVisibleTextTracksChanged
+    };
+    void configureTextTrackDisplay(ConfigureTextTrackDisplayFlags = DoNotAssumeVisibleTextTracksChanged);

[acolwell GONE FROM CHROMIUM, 2013/08/12 20:19:02]

nit: Do you really need the default argument value here? There appears to be
only two call sites for this method. Any reason not to just explicitly specify
it at the call site that needs it?

[vcarbune.chromium, 2013/08/19 22:20:12]

No, explicitly passed it at each function call.

     void updateTextTrackDisplay();
 
     // TextTrackClient