Fix docked browser window sometimes appears onscreen after restart

(Continuing from original cl https://codereview.chromium.org/1055893003 .)

Change IsMaximized() to return false if the window is in the dock, and
a unit test to make sure this is always the case. It turns out
-isZoomed can sometimes return YES for a docked window, which
sometimes results in the window becoming undocked on the next restart.
Please read the long entry in the bug report for a complete explanation
of how the change fixes the problem.

BUG=452976

Review URL: https://codereview.chromium.org/1062053002

Cr-Commit-Position: refs/heads/master@{#324079}

chrome/browser/ui/cocoa/browser_window_cocoa.mm

@@ -363,7 +363,10 @@ gfx::Rect BrowserWindowCocoa::GetBounds() const {
 }
 
 bool BrowserWindowCocoa::IsMaximized() const {
-  return [window() isZoomed];
+  // -isZoomed returns YES if the window's frame equals the rect returned by
+  // -windowWillUseStandardFrame:defaultFrame:, even if the window is in the
+  // dock, so have to explicitly check for miniaturization state first.
+  return ![window() isMiniaturized] && [window() isZoomed];
 }
 
 bool BrowserWindowCocoa::IsMinimized() const {

chrome/browser/ui/cocoa/browser_window_cocoa_unittest.mm

@@ -48,6 +48,22 @@ TEST_F(BrowserWindowCocoaTest, TestBookmarkBarVisible) {
   EXPECT_EQ(before, bwc->IsBookmarkBarVisible());
 }
 
+// Test that IsMaximized() returns false when the browser window goes from
+// maximized to minimized state - http://crbug/452976.
+TEST_F(BrowserWindowCocoaTest, TestMinimizeState) {
+  scoped_ptr<BrowserWindowCocoa> bwc(
+      new BrowserWindowCocoa(browser(), controller_));
+
+  EXPECT_FALSE(bwc->IsMinimized());
+  bwc->Maximize();
+  EXPECT_TRUE(bwc->IsMaximized());
+  EXPECT_FALSE(bwc->IsMinimized());
+  bwc->Minimize();
+  EXPECT_FALSE(bwc->IsMaximized());
+  EXPECT_TRUE(bwc->IsMinimized());
+  bwc->Restore();
+}
+
 // Tests that BrowserWindowCocoa::Close mimics the behavior of
 // -[NSWindow performClose:].
 class BrowserWindowCocoaCloseTest : public CocoaProfileTest {

chrome/browser/ui/cocoa/browser_window_controller.mm

@@ -727,6 +727,8 @@ using content::WebContents;
 // browsers' behaviour, and is desirable in multi-tab situations. Note, however,
 // that the "toggle" behaviour means that the window can still be "unzoomed" to
 // the user size.
+// Note: this method is also called from -isZoomed. If the returned zoomed rect
+// equals the current window's frame, -isZoomed returns YES.
 - (NSRect)windowWillUseStandardFrame:(NSWindow*)window
                         defaultFrame:(NSRect)frame {
   // Forget that we grew the window up (if we in fact did).