Refactor OpaqueBrowserFrameView; reduce uses of kUseSystemTitleBar.

chrome/browser/ui/views/frame/opaque_browser_frame_view_layout.cc

Index: chrome/browser/ui/views/frame/opaque_browser_frame_view_layout.cc
diff --git a/chrome/browser/ui/views/frame/opaque_browser_frame_view_layout.cc b/chrome/browser/ui/views/frame/opaque_browser_frame_view_layout.cc
index 8d32d1125d5d665a456ff2b7b0cbe4dec445c5a4..41534a5d46595a6fdae1dc22c6bb1432675615ef 100644
--- a/chrome/browser/ui/views/frame/opaque_browser_frame_view_layout.cc
+++ b/chrome/browser/ui/views/frame/opaque_browser_frame_view_layout.cc
@@ -268,12 +268,10 @@ gfx::Rect OpaqueBrowserFrameViewLayout::CalculateClientAreaBounds(
 }
 
 bool OpaqueBrowserFrameViewLayout::IsTitleBarCondensed() const {
-#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
-  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kUseSystemTitleBar))
-    return true;
-#endif
-
-  return delegate_->IsMaximized();
+  // If there are no caption buttons, there is no need to have an uncondensed
+  // title bar. If the window is maximized, the title bar is condensed
+  // regardless of whether there are caption buttons.
+  return !delegate_->ShouldShowCaptionButtons() || delegate_->IsMaximized();

[Matt Giuca, 2014/01/24 05:55:11]

Detailed logic as to why this does not change any behaviour:

On Linux, this is equivalent to:
  kUseSystemTitleBar || (UnityIsRunning && IsMaximized) || IsMaximized
= kUseSystemTitleBar || IsMaximized

On Windows 8, this is equivalent to:
  IsSingleWindowMetroMode || IsMaximized
= IsMaximized

On other platforms, this is equivalent to:
  IsMaximized

So this refactor gives the same logic as before (but with the bonus of
offloading the decision about the kUseSystemTitleBar switch to
OpaqueBrowserFrameView).

I believe this has good future-proof semantics. The rationale for NOT condensing
the title bar is because you want extra room to display the caption buttons, so
I believe the new logic captures the intent of condensing the title bar as well
as the existing behaviour.

 }
 
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