Mac: Fix theme image drawing when building with >=10.9 SDK.

chrome/browser/ui/cocoa/tabs/tab_window_controller.mm

Index: chrome/browser/ui/cocoa/tabs/tab_window_controller.mm
diff --git a/chrome/browser/ui/cocoa/tabs/tab_window_controller.mm b/chrome/browser/ui/cocoa/tabs/tab_window_controller.mm
index 103c740d49970350b4a33c23d30aee692021056e..6f03ffdeb473f79fe0dec7bbf6b364ae1900a253 100644
--- a/chrome/browser/ui/cocoa/tabs/tab_window_controller.mm
+++ b/chrome/browser/ui/cocoa/tabs/tab_window_controller.mm
@@ -8,6 +8,7 @@
 #import "chrome/browser/ui/cocoa/browser_window_layout.h"
 #import "chrome/browser/ui/cocoa/fast_resize_view.h"
 #import "chrome/browser/ui/cocoa/framed_browser_window.h"
+#import "chrome/browser/ui/cocoa/tabs/tab_strip_background_view.h"
 #import "chrome/browser/ui/cocoa/tabs/tab_strip_view.h"
 #import "chrome/browser/ui/cocoa/themed_window.h"
 #import "chrome/browser/ui/cocoa/version_independent_window.h"
@@ -65,6 +66,23 @@
                                          NSViewHeightSizable];
     [[[self window] contentView] addSubview:tabContentArea_];
 
+    // tabStripBackgroundView_ draws the theme image behind the tab strip area.
+    // When making a tab dragging window (setUseOverlay:), this view stays in
+    // the parent window so that it can be translucent, while the tab strip view
+    // moves to the child window and stays opaque.
+    NSView* windowView = [window cr_windowView];
+    tabStripBackgroundView_.reset([[TabStripBackgroundView alloc]

[erikchen, 2014/09/27 00:23:33]

When the tab strip gets moved to another window (e.g. immersive fullscreen),
won't this view have to be moved as well?

[Andre, 2014/09/27 18:17:02]

I don't think this view needs to be moved.
FullscreenWindow is not a subclass of FramedBrowserWindow, so it was not
getting this custom drawing before. Instead it is using FloatingBarBackingView
to draw the background.

+        initWithFrame:NSMakeRect(0,
+                                 NSMaxY([windowView bounds]) -
+                                     kBrowserFrameViewPaintHeight,
+                                 NSWidth([windowView bounds]),
+                                 kBrowserFrameViewPaintHeight)]);
+    [tabStripBackgroundView_
+        setAutoresizingMask:NSViewWidthSizable | NSViewMinYMargin];
+    [windowView addSubview:tabStripBackgroundView_
+                positioned:NSWindowBelow
+                relativeTo:nil];
+
     tabStripView_.reset([[TabStripView alloc]
         initWithFrame:NSMakeRect(0, 0, 750, chrome::kTabStripHeight)]);
     [tabStripView_ setAutoresizingMask:NSViewWidthSizable |