Allow some InputConnection methods to be called on UI thread

Assertions are removed from some of the InputConnection methods that
merely post on UI thread. In doing so, mPendingAccent was changed to be
accessed only on UI thread.

However, beginBatchEdit() / endBatchEdit() implementations are quite
complicated and no evidence calling those on UI thread was found so far.

Also, for get* methods we return cached results.

BUG=643477

Review-Url: https://codereview.chromium.org/2299913003
Cr-Commit-Position: refs/heads/master@{#417499}

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

@@ -1350,6 +1350,30 @@ public class ImeTest extends ContentShellTestBase {
         waitAndVerifyUpdateSelection(0, 7, 7, -1, -1);
     }
 
+    // crbug.com/643477
+    @MediumTest
+    @Feature({"TextInput"})
+    public void testUiThreadAccess() throws Exception {
+        final ChromiumBaseInputConnection connection = mConnection;
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            @Override
+            public void run() {
+                // We allow UI thread access for most functions, except for
+                // beginBatchEdit(), endBatchEdit(), and get* methods().
+                assertTrue(connection.commitText("a", 1));
+                assertTrue(connection.setComposingText("b", 1));
+                assertTrue(connection.setComposingText("bc", 1));
+                assertTrue(connection.finishComposingText());
+            }
+        });
+        assertEquals("abc", runBlockingOnImeThread(new Callable<CharSequence>() {
+            @Override
+            public CharSequence call() throws Exception {
+                return connection.getTextBeforeCursor(5, 0);
+            }
+        }));
+    }
+
     private void performGo(TestCallbackHelperContainer testCallbackHelperContainer)
             throws Throwable {
         final InputConnection inputConnection = mConnection;

content/public/android/junit/src/org/chromium/content/browser/input/ThreadedInputConnectionTest.java

@@ -6,6 +6,7 @@ package org.chromium.content.browser.input;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
@@ -32,6 +33,8 @@ import org.mockito.Mockito;
 import org.mockito.MockitoAnnotations;
 import org.robolectric.annotation.Config;
 
+import java.util.concurrent.Callable;
+
 /**
  * Unit tests for {@ThreadedInputConnection}.
  */
@@ -44,6 +47,7 @@ public class ThreadedInputConnectionTest {
     InOrder mInOrder;
     View mView;
     Context mContext;
+    boolean mRunningOnUiThread;
 
     @Before
     public void setUp() throws Exception {
@@ -59,7 +63,12 @@ public class ThreadedInputConnectionTest {
         when(mContext.getSystemService(Context.INPUT_METHOD_SERVICE)).thenReturn(Mockito.mock(
                 InputMethodManager.class));
         // Let's create Handler for test thread and pretend that it is running on IME thread.
-        mConnection = new ThreadedInputConnection(mView, mImeAdapter, new Handler());
+        mConnection = new ThreadedInputConnection(mView, mImeAdapter, new Handler()) {
+            @Override
+            protected boolean runningOnUiThread() {
+                return mRunningOnUiThread;
+            }
+        };
     }
 
     @Test
@@ -103,7 +112,7 @@ public class ThreadedInputConnectionTest {
     @Feature({"TextInput"})
     public void testPressingDeadKey() {
         // On default keyboard "Alt+i" produces a dead key '\u0302'.
-        mConnection.setCombiningAccent(0x0302);
+        mConnection.setCombiningAccentOnUiThread(0x0302);
         mConnection.updateComposingText("\u0302", 1, true);
         mInOrder.verify(mImeAdapter)
                 .sendCompositionToNative(
@@ -186,4 +195,31 @@ public class ThreadedInputConnectionTest {
         // Should not hang here. Return null to indicate failure.
         assertEquals(null, mConnection.getTextBeforeCursor(10, 0));
     }
+
+    // crbug.com/643477
+    @Test
+    @Feature({"TextInput"})
+    public void testUiThreadAccess() {
+        assertTrue(mConnection.commitText("hello", 1));
+        mRunningOnUiThread = true;
+        // Depending on the timing, the result may not be up-to-date.
+        assertNotEquals("hello",
+                ThreadUtils.runOnUiThreadBlockingNoException(new Callable<CharSequence>() {
+                    @Override
+                    public CharSequence call() {
+                        return mConnection.getTextBeforeCursor(10, 0);
+                    }
+                }));
+        // Or it could be.
+        mConnection.updateStateOnUiThread("hello", 5, 5, -1, -1, true, true);
+        assertEquals("hello",
+                ThreadUtils.runOnUiThreadBlockingNoException(new Callable<CharSequence>() {
+                    @Override
+                    public CharSequence call() {
+                        return mConnection.getTextBeforeCursor(10, 0);
+                    }
+                }));
+
+        mRunningOnUiThread = false;
+    }
 }