Browser goes to the previous page when exiting fullscreen via escape(esc) key of BT keyboard

Browser should go back to video page(having inline video) through
escape key of BT keyboard instead of goig back to main page.

BUG=396996

Review URL: https://codereview.chromium.org/439433004

Cr-Commit-Position: refs/heads/master@{#293181}

content/public/android/java/src/org/chromium/content/browser/ContentVideoViewLegacy.java

@@ -127,8 +127,8 @@ public class ContentVideoViewLegacy extends ContentVideoView {
                     } else {
                         toggleMediaControlsVisiblity();
                     }
-                } else if (keyCode == KeyEvent.KEYCODE_BACK &&
-                        event.getAction() == KeyEvent.ACTION_UP) {
+                } else if ((keyCode == KeyEvent.KEYCODE_BACK || keyCode == KeyEvent.KEYCODE_ESCAPE)
+                        && event.getAction() == KeyEvent.ACTION_UP) {
                     exitFullscreen(false);
                     return true;
                 } else if (keyCode == KeyEvent.KEYCODE_MENU || keyCode == KeyEvent.KEYCODE_SEARCH) {