cros-md: Remove the non-MD immersive mode code paths

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

Index: chrome/browser/ui/views/frame/browser_view_layout.cc
diff --git a/chrome/browser/ui/views/frame/browser_view_layout.cc b/chrome/browser/ui/views/frame/browser_view_layout.cc
index 8ad5c754eacdec1469e07bfbb11791d3857d876a..47a17fee191dbf3462f064873fcb9efb7c39830f 100644
--- a/chrome/browser/ui/views/frame/browser_view_layout.cc
+++ b/chrome/browser/ui/views/frame/browser_view_layout.cc
@@ -23,7 +23,6 @@
 #include "chrome/browser/ui/views/tabs/tab_strip.h"
 #include "components/web_modal/web_contents_modal_dialog_host.h"
 #include "ui/base/hit_test.h"
-#include "ui/base/material_design/material_design_controller.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/scrollbar_size.h"
@@ -489,6 +488,13 @@ void BrowserViewLayout::UpdateTopContainerBounds() {
       height = child_bottom;
   }
 
+  // For immersive fullscreen, tabstrip is considered visible. During the
+  // |height| update, the non-zero |height| should return to zero instead.
+  if (immersive_mode_controller_->IsEnabled() &&

[sky, 2017/02/13 16:57:19]

How did pre-md immersive inject a height of 3?

[Qiang(Joe) Xu, 2017/02/13 21:21:08]

It is because:
https://cs.chromium.org/chromium/src/chrome/browser/ui/views/frame/browser_no...,
the call of GetPreferredSize(),
which is
https://cs.chromium.org/chromium/src/chrome/browser/ui/views/tabs/tab_strip.c...

Thanks for asking me. Before, when I am doing logging, I blamed the height
change from 3 to 29 on tabstrip visible. But actually the root cause is here,
immersive_style_ is always false now (we should remove it actually), which makes
the preferred size using Tab::GetMinimumInactiveSize().height(). We should now
make it switch between 0 and Tab::GetMinimumInactiveSize().height().

Let me think how to do it gracefully. Should we remove |immersive_style_| in
this CL?

+      !immersive_mode_controller_->IsRevealed()) {
+    height = 0;
+  }
+
   // Ensure that the top container view reaches the topmost view in the
   // ClientView because the bounds of the top container view are used in
   // layout and we assume that this is the case.