[IME] Stop sending synthesized keyCode, and send 229 instead.

Previously for <input> with autocomplete="off", we send a synthesized keyCode.
This CL disables this feature to send 229 instead (however, backspace still
generates 8).

BUG=476497

Review URL: https://codereview.chromium.org/1082823002

Cr-Commit-Position: refs/heads/master@{#325524}

content/public/android/java/src/org/chromium/content/browser/input/ImeAdapter.java

@@ -433,12 +433,9 @@ public class ImeAdapter {
                                 KeyEvent.changeAction(keyEvent, KeyEvent.ACTION_UP), 0);
             }
 
-            // If we do not have autocomplete=off, then always send compose events rather than a
-            // guessed keyCode. This addresses http://crbug.com/422685 .
-            if ((mTextInputFlags & WebTextInputFlags.AutocompleteOff) == 0) {
-                keyCode = COMPOSITION_KEY_CODE;
-                modifiers = 0;
-            }
+            // Always send compose events. This is a quick fix for http://crbug.com/476497.
+            keyCode = COMPOSITION_KEY_CODE;
+            modifiers = 0;
 
             // When typing, there is no issue sending KeyDown and KeyUp events around the
             // composition event because those key events do nothing (other than call JS

content/public/android/javatests/src/org/chromium/content/browser/input/ImeTest.java

@@ -737,10 +737,11 @@ public class ImeTest extends ContentShellTestBase {
         waitAndVerifyEditableCallback(mConnection.mImeUpdateQueue, 0, "", 0, 0, -1, -1);
 
         // H
-        // Since autocomplete="off", regular key codes are emitted.
+        // Although autocomplete="off", we still emit COMPOSITION_KEY_CODE since synthesized
+        // keycodes are disabled.
         expectUpdateStateCall(mConnection);
         setComposingText(mConnection, "h", 1);
-        assertEquals(KeyEvent.KEYCODE_H, mImeAdapter.mLastSyntheticKeyCode);
+        assertEquals(COMPOSITION_KEY_CODE, mImeAdapter.mLastSyntheticKeyCode);
 
         // Simulate switch of input fields.
         finishComposingText(mConnection);
@@ -748,7 +749,7 @@ public class ImeTest extends ContentShellTestBase {
         // H
         expectUpdateStateCall(mConnection);
         setComposingText(mConnection, "h", 1);
-        assertEquals(KeyEvent.KEYCODE_H, mImeAdapter.mLastSyntheticKeyCode);
+        assertEquals(COMPOSITION_KEY_CODE, mImeAdapter.mLastSyntheticKeyCode);
     }
 
     @SmallTest