Fix the Views-GTK build by adding necessary tab_strip_2 files and fixing some compilation errors.

chrome/browser/views/frame/browser_frame_gtk.cc

Index: chrome/browser/views/frame/browser_frame_gtk.cc
diff --git a/chrome/browser/views/frame/browser_frame_gtk.cc b/chrome/browser/views/frame/browser_frame_gtk.cc
index 967a1dcd8ef0c6b6f5b248e4158b9fb60631c3a9..c3686b225d42435578f9541d3d5359fa61f0ba69 100644
--- a/chrome/browser/views/frame/browser_frame_gtk.cc
+++ b/chrome/browser/views/frame/browser_frame_gtk.cc
@@ -59,6 +59,10 @@ void BrowserFrameGtk::UpdateThrobber(bool running) {
   browser_frame_view_->UpdateThrobber(running);
 }
 
+void BrowserFrameGtk::ContinueDraggingDetachedTab() {
+  NOTIMPLEMENTED();
+}
+
 ThemeProvider* BrowserFrameGtk::GetThemeProviderForFrame() const {
   // This is implemented for a different interface than GetThemeProvider is,
   // but they mean the same things.