[Mac] With the new avatar button, tabs do not expand to fill bar in fullscreen

When in fullscreen we should give back the fullscreen icon's width to the tabstrip.

Before: https://drive.google.com/open?id=0B1B1Up4p2NRMdXloQ3phSElBeEk&authuser=1
After: https://drive.google.com/open?id=0B1B1Up4p2NRMM2JNRE56aC1uRDA&authuser=1

BUG=403561

Review URL: https://codereview.chromium.org/493803002

Cr-Commit-Position: refs/heads/master@{#291162}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@291162 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/cocoa/browser_window_controller_private.mm

@@ -357,10 +357,16 @@ willPositionSheet:(NSWindow*)sheet
         static_cast<FramedBrowserWindow*>([self window]);
     rightIndent += -[window fullScreenButtonOriginAdjustment].x;
 
-    // The new avatar is wider than the default indentation, so we need to
-    // account for its width.
-    if ([self shouldUseNewAvatarButton])
+    if ([self shouldUseNewAvatarButton]) {
+      // The new avatar is wider than the default indentation, so we need to
+      // account for its width.
       rightIndent += NSWidth([avatarButton frame]) + kAvatarTabStripShrink;
+
+      // When the fullscreen icon is not displayed, return its width to the
+      // tabstrip.
+      if ([self isFullscreen])
+        rightIndent -= kFullscreenIconWidth;
+    }
   } else if ([self shouldShowAvatar]) {
     rightIndent += kAvatarTabStripShrink +
         NSWidth([avatarButton frame]) + kAvatarRightOffset;