Prevent thread assertion for HTC mail apk

android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java

Index: android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java
diff --git a/android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java b/android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java
index 0f8ca85b46b4b6dc8b195baf1c92a20f3a56962e..1e7c0ed8bb9a341093c8bf8690ff433c7ecee195 100644
--- a/android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java
+++ b/android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java
@@ -8,6 +8,7 @@ import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.content.Context;
 import android.content.Intent;
+import android.content.pm.PackageInfo;
 import android.content.res.Configuration;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
@@ -62,9 +63,11 @@ import org.chromium.content_public.browser.NavigationHistory;
 
 import java.io.BufferedWriter;
 import java.io.File;
+import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.Map;
 import java.util.concurrent.Callable;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * This class is the delegate to which WebViewProxy forwards all API calls.
@@ -102,6 +105,8 @@ class WebViewChromium implements WebViewProvider, WebViewProvider.ScrollDelegate
 
     private WebViewChromiumFactoryProvider mFactory;
 
+    private static volatile AtomicBoolean sIsHtcMail = new AtomicBoolean(false);
+
     private static boolean sRecordWholeDocumentEnabledByApi = false;
     static void enableSlowWholeDocumentDraw() {
         sRecordWholeDocumentEnabledByApi = true;
@@ -135,6 +140,8 @@ class WebViewChromium implements WebViewProvider, WebViewProvider.ScrollDelegate
     @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     public void init(final Map<String, Object> javaScriptInterfaces,
             final boolean privateBrowsing) {
+        sIsHtcMail.set(isHtcMail(mWebView.getContext()));
+        if (sIsHtcMail.get()) disableThreadChecking();
         if (privateBrowsing) {
             mFactory.startYourEngines(true);
             final String msg = "Private browsing is not supported in WebView.";
@@ -198,6 +205,44 @@ class WebViewChromium implements WebViewProvider, WebViewProvider.ScrollDelegate
         });
     }
 
+    private boolean isHtcMail(Context context) {
+        if (mAppTargetSdkVersion > Build.VERSION_CODES.M) return false;

[Torne, 2016/08/12 13:25:41]

I'm not sure that checking the target SDK version is correct throughout this
function, though it's unclear from the information they have provided. We might
need to be checking the build version of the actual OS instead/as well,
depending exactly how their versioning works.

[Changwan Ryu, 2016/08/16 10:30:24]

You're right. Fixed now.

+        final String htcMailPackageId = "com.htc.android.mail";
+        if (!htcMailPackageId.equals(context.getPackageName())) return false;
+
+        try {
+            PackageInfo packageInfo =
+                    context.getPackageManager().getPackageInfo(htcMailPackageId, 0);
+            // These values are provided by HTC.
+            if ((mAppTargetSdkVersion < Build.VERSION_CODES.M
+                    && packageInfo.versionCode < 864021756)
+                    || packageInfo.versionCode < 866001861) {
+                Log.w(TAG, "Disabling thread check in WebView (http://crbug.com/622151). "
+                        + "APK name: " + htcMailPackageId + ", versionCode: "
+                        + packageInfo.versionCode);
+                return true;
+            }
+        } catch (Exception e) {

[Torne, 2016/08/12 13:25:41]

Comment or something here to note that we are intentionally swallowing it, and
ideally catch a more specific exception type (the ones the package manager
actually throws).

[Changwan Ryu, 2016/08/16 10:30:24]

Done.

+        }
+        return false;
+    }
+
+    // This is a workaround for https://crbug.com/622151.
+    // In HTC's email app, InputConnection.setComposingText() will call WebView.evaluateJavaScript,
+    // and thread assertion will occur. We turn off WebView thread assertion for this app.
+    private void disableThreadChecking() {
+        try {
+            Class webViewClass = Class.forName("android.webkit.WebView");
+            Field field = webViewClass.getDeclaredField("sEnforceThreadChecking");
+            field.setAccessible(true);
+            field.setBoolean(null, false);
+            field.setAccessible(false);
+        } catch (ClassNotFoundException | NoSuchFieldException | IllegalAccessException
+                | IllegalArgumentException e) {
+            Log.w(TAG, "Failed to disable thread checking.");
+        }
+    }
+
     private void initForReal() {
         AwContentsStatics.setRecordFullDocument(sRecordWholeDocumentEnabledByApi
                 || mAppTargetSdkVersion < Build.VERSION_CODES.LOLLIPOP);
@@ -540,9 +585,20 @@ class WebViewChromium implements WebViewProvider, WebViewProvider.ScrollDelegate
         mAwContents.loadDataWithBaseURL(baseUrl, data, mimeType, encoding, historyUrl);
     }
 
-    public void evaluateJavaScript(String script, ValueCallback<String> resultCallback) {
-        checkThread();
-        mAwContents.evaluateJavaScript(script, resultCallback);
+    public void evaluateJavaScript(
+            final String script, final ValueCallback<String> resultCallback) {
+        if (sIsHtcMail.get()) {
+            // This is a workaround for https://crbug.com/622151.
+            ThreadUtils.runOnUiThread(new Runnable() {

[Torne, 2016/08/12 13:25:41]

Every other function here uses checkNeedsPost and mFactory.runOnUiThreadBlocking
or mFactory.addTask as appropriate. Is there a problem with doing the same here?

[Changwan Ryu, 2016/08/16 10:30:24]

Done.

+                @Override
+                public void run() {
+                    mAwContents.evaluateJavaScript(script, resultCallback);
+                }
+            });
+        } else {
+            checkThread();
+            mAwContents.evaluateJavaScript(script, resultCallback);
+        }
     }
 
     @Override