[Printing] Return early in pdfWritingDone() if there is no printing task

pdfWritingDone() will be called even there is no printing task. This is
because native will report printing failure as |pageCount| = 0 for
pdfWritingDone().

This CL makes pdfWritingDone() do the clean up tasks for only
PRINTING_STATE_STARTED_FROM_ONWRITE state.

Bug: 974581
Change-Id: Id69025ecdd2b874e0412b1dbabdb9a00b3a252f2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1674689
Commit-Queue: Shimi Zhang <ctzsm@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672551}

chrome/android/javatests/src/org/chromium/chrome/browser/printing/PrintingControllerTest.java

@@ -15,6 +15,7 @@ import android.print.PrintDocumentAdapter;
 import android.print.PrintDocumentInfo;
 import android.support.test.filters.LargeTest;
 import android.support.test.filters.MediumTest;
+import android.support.test.filters.SmallTest;
 
 import org.junit.Assert;
 import org.junit.Before;
@@ -379,6 +380,25 @@ public class PrintingControllerTest {
         }
     }
 
+    /**
+     * Regresstion test for crbug.com/974581. In some cases, native printing code will fail without
+     * starting a printing task in Java side. pdfWritingDone() will be called with |pageCount| = 0
+     * in this case. We don't need to do anything for this in Java side for now.
+     */
+    @Test
+    @SmallTest
+    @Feature({"Printing"})
+    public void testPdfWritingDoneCalledWithoutInitailizePrintingTask() throws Throwable {
+        if (!ApiCompatibilityUtils.isPrintingSupported()) return;
+
+        mActivityTestRule.startMainActivityWithURL(URL);
+        final PrintingControllerImpl controller = createControllerOnUiThread();
+
+        // Calling pdfWritingDone() with |pageCount| = 0 before onWrite() was called. It shouldn't
+        // crash.
+        TestThreadUtils.runOnUiThreadBlocking(() -> controller.pdfWritingDone(0));
+    }
+
     private PrintingControllerImpl createControllerOnUiThread() {
         return TestThreadUtils.runOnUiThreadBlockingNoException(() -> {
             return (PrintingControllerImpl) PrintingControllerImpl.create(

printing/android/java/src/org/chromium/printing/PrintingControllerImpl.java

@@ -213,7 +213,13 @@ public class PrintingControllerImpl implements PrintingController, PdfGenerator
 
     @Override
     public void pdfWritingDone(int pageCount) {
-        if (mPrintingState == PRINTING_STATE_FINISHED) return;
+        if (mPrintingState == PRINTING_STATE_READY) {
+            assert pageCount
+                    == 0 : "There is no pending printing task, should only be a failure report";
+        }
+
+        if (mPrintingState != PRINTING_STATE_STARTED_FROM_ONWRITE) return;
+
         mPrintingState = PRINTING_STATE_READY;
         closeFileDescriptor();
         if (pageCount > 0) {