Fix ChromeSwitches.DISABLE_FULLSCREEN to not overlap content.

chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java

Index: chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java b/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
index a88063610d22b56e782c5cfaddd3ccf9e09ac6ea..71261bd414e2baecb3ab90ac98fbf18995433d36 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
@@ -66,6 +66,7 @@ import org.chromium.chrome.browser.contextmenu.ContextMenuPopulator;
 import org.chromium.chrome.browser.contextmenu.ContextMenuPopulatorWrapper;
 import org.chromium.chrome.browser.crash.MinidumpUploadService;
 import org.chromium.chrome.browser.customtabs.CustomTabActivity;
+import org.chromium.chrome.browser.device.DeviceClassManager;
 import org.chromium.chrome.browser.document.DocumentUtils;
 import org.chromium.chrome.browser.document.DocumentWebContentsDelegate;
 import org.chromium.chrome.browser.download.ChromeDownloadDelegate;
@@ -2924,6 +2925,7 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
         enableHidingTopControls &= !mIsShowingErrorPage;
         enableHidingTopControls &= !webContents.isShowingInterstitialPage();
         enableHidingTopControls &= (mFullscreenManager != null);
+        enableHidingTopControls &= DeviceClassManager.enableFullscreen();
 
         return enableHidingTopControls;
     }