Add a test that verifies that the active WebContents is shown

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

Index: chrome/browser/ui/views/frame/browser_view_browsertest.cc
diff --git a/chrome/browser/ui/views/frame/browser_view_browsertest.cc b/chrome/browser/ui/views/frame/browser_view_browsertest.cc
index 07ce7982dfbfd82f11b2450f58b6460309b5a359..888f8ba3bd208e18155d4e57eeed270cc11601c8 100644
--- a/chrome/browser/ui/views/frame/browser_view_browsertest.cc
+++ b/chrome/browser/ui/views/frame/browser_view_browsertest.cc
@@ -18,6 +18,7 @@
 #include "content/public/browser/invalidate_type.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_observer.h"
+#include "ui/base/ui_base_types.h"
 
 class BrowserViewTest : public InProcessBrowserTest {
  public:
@@ -78,6 +79,35 @@ class TestWebContentsObserver : public content::WebContentsObserver {
   DISALLOW_COPY_AND_ASSIGN(TestWebContentsObserver);
 };
 
+class WebContentsShowHideObserver : public content::WebContentsObserver {
+ public:
+  WebContentsShowHideObserver(content::WebContents* web_contents,
+                              const base::Closure& callback)
+      : WebContentsObserver(web_contents),
+        callback_(callback),
+        show_state_(ui::SHOW_STATE_DEFAULT) {}
+
+  // WebContentsObserver.
+  virtual void WasHidden() override {
+    show_state_ = ui::SHOW_STATE_INACTIVE;
+    callback_.Run();
+  }
+
+  virtual void WasShown() override {
+    show_state_ = ui::SHOW_STATE_NORMAL;
+    callback_.Run();
+  }
+
+  bool shown() { return show_state_ == ui::SHOW_STATE_NORMAL; }
+  bool hidden() { return show_state_ == ui::SHOW_STATE_INACTIVE; }
+
+ private:
+  base::Closure callback_;
+  ui::WindowShowState show_state_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebContentsShowHideObserver);
+};
+
 }  // namespace
 
 // Verifies don't crash when CloseNow() is invoked with two tabs in a browser.
@@ -237,3 +267,37 @@ IN_PROC_BROWSER_TEST_F(BrowserViewTest, AvoidUnnecessaryVisibilityChanges) {
 
   browser_view()->bookmark_bar()->RemoveObserver(&observer);
 }
+
+IN_PROC_BROWSER_TEST_F(BrowserViewTest, MinimizeHidesWebContents) {
+  // Minimizing the window should cause the active WebContents to be hidden.
+  {
+    base::RunLoop run_loop;
+    WebContentsShowHideObserver observed(
+        browser()->tab_strip_model()->GetActiveWebContents(),
+        run_loop.QuitClosure());
+
+    ASSERT_FALSE(observed.hidden());
+    ASSERT_FALSE(observed.shown());
+    browser()->window()->Minimize();
+    if (!observed.hidden())
+      run_loop.Run();
+    ASSERT_TRUE(observed.hidden());
+    ASSERT_FALSE(observed.shown());
+  }
+
+  // Restoring the window should cause the active WebContents to be shown.
+  {
+    base::RunLoop run_loop;
+    WebContentsShowHideObserver observed(
+        browser()->tab_strip_model()->GetActiveWebContents(),
+        run_loop.QuitClosure());
+
+    ASSERT_FALSE(observed.hidden());
+    ASSERT_FALSE(observed.shown());
+    browser()->window()->Restore();
+    if (!observed.shown())
+      run_loop.Run();
+    ASSERT_TRUE(observed.shown());
+    ASSERT_FALSE(observed.hidden());
+  }
+}