Added code to dismiss url suggestion popup on back key press.

chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellToolbar.java

Index: chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellToolbar.java
diff --git a/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellToolbar.java b/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellToolbar.java
index a88405063d3727f264b9f1226c9c57c1cb2bc31c..a4fbf2d71cd3f5b1253d99aabcefe5e1fec1a21f 100644
--- a/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellToolbar.java
+++ b/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellToolbar.java
@@ -140,6 +140,19 @@ public class ChromeShellToolbar extends LinearLayout {
                 }
             }
         });
+        mUrlTextView.setOnKeyListener(new OnKeyListener() {
+            @Override
+            public boolean onKey(View v, int keyCode, KeyEvent event) {
+                if (keyCode == KeyEvent.KEYCODE_BACK) {
+                    mUrlTextView.clearFocus();
+                    if (mTab != null) {
+                        mTab.getView().requestFocus();
+                    }
+                    return true;
+                }
+                return false;
+            }
+        });
 
         mSuggestionPopup = new SuggestionPopup(getContext(), mUrlTextView, this);
         mUrlTextView.addTextChangedListener(mSuggestionPopup);