BitmapImage: Use the cheapest Vector constructor.

Source/platform/graphics/BitmapImage.cpp

Index: Source/platform/graphics/BitmapImage.cpp
diff --git a/Source/platform/graphics/BitmapImage.cpp b/Source/platform/graphics/BitmapImage.cpp
index 29904b21ceff4c47b77eecdbf73513d0fa5d1ae0..6fd6cbbe3ef4c1ff33d5758f09e583f46054cd17 100644
--- a/Source/platform/graphics/BitmapImage.cpp
+++ b/Source/platform/graphics/BitmapImage.cpp
@@ -44,7 +44,7 @@ namespace WebCore {
 BitmapImage::BitmapImage(ImageObserver* observer)
     : Image(observer)
     , m_currentFrame(0)
-    , m_frames(0)
+    , m_frames()

[jamesr, 2014/08/07 17:38:29]

why not just remove this line completely?

[Daniel Bratell, 2014/08/26 09:05:17]

It is a question of style, but in the work I've been doing performance have been
noticeably affected by code in Vector constructors and destructors so I felt it
was beneficial to list all the work done when the constructor runs. But it's a
question of style so I don't have any strong opinions.

     , m_frameTimer(0)
     , m_repetitionCount(cAnimationNone)
     , m_repetitionCountStatus(Unknown)