[Printing] Change |showSystemDialogDone()| timing

In |window.print()| code path for Android, we have the call stack like
this:

  PrintJobWorker::GetSettingsWithUI() ->
  PrintingContextAndroid::AskUserForSettings() ->
  PrintingContext.showPrintDialog() (Java)

We have set |callback_| in |PrintingContextAndroid| to be
|PrintJobWorker::GetSettingsDone()|, but didn't call it in later stage
unless something fails.

This CL makes |PrintingControllerImpl| call
|PrintingContext.showSystemDialogDone()| no matter what happens. This is
because the first |GetSettingsWithUI()| for |window.print()| on Android
is only to wake up |PrintManager| to start printing job. We will set
the real settings in later |GetSettingsWithUI()| call.

Bug: 863297
Change-Id: I3be0a3dceab134db7a47e0c1b48ccd1802e74447
Reviewed-on: https://chromium-review.googlesource.com/1162754Reviewed-by: Changwan Ryu <changwan@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Shimi Zhang <ctzsm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582980}

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

@@ -246,7 +246,7 @@ public class PrintingControllerTest {
                     new TabPrinter(currentTab), mockPrintManagerDelegate, -1, -1);
             TabModelUtils.closeCurrentTab(mActivityTestRule.getActivity().getCurrentTabModel());
             Assert.assertFalse("currentTab should be closed already.", currentTab.isInitialized());
-            printingController.startPendingPrint(null);
+            printingController.startPendingPrint();
         });
     }
 

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

@@ -87,16 +87,16 @@ public class PrintingContext implements PrintingContextInterface {
         return mController.getPageHeight();
     }
 
+    // Called along window.print() path to initialize a printing job.
     @CalledByNative
     public void showPrintDialog() {
         ThreadUtils.assertOnUiThread();
         if (mController != null) {  // The native side doesn't check if printing is enabled
-            mController.startPendingPrint(this);
-        } else {
-            Log.d(TAG, "Unable to start printing, feature not available.");
-            // Printing disabled. Notify the native side to stop waiting.
-            showSystemDialogDone();
+            mController.startPendingPrint();
         }
+        // Reply to native side with |CANCEL| since there is no printing settings available yet at
+        // this stage.
+        showSystemDialogDone();
     }
 
     @CalledByNative
@@ -139,8 +139,8 @@ public class PrintingContext implements PrintingContextInterface {
         nativeAskUserForSettingsReply(mNativeObject, success);
     }
 
-    @Override
-    public void showSystemDialogDone() {
+    private void showSystemDialogDone() {
+        assert mNativeObject != 0;
         nativeShowSystemDialogDone(mNativeObject);
     }
 

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

@@ -15,10 +15,4 @@ public interface PrintingContextInterface {
      * @param delete If true, delete the entry (if it exists).  If false, add it to the map.
      */
     void updatePrintingContextMap(int fileDescriptor, boolean delete);
-
-    /**
-     * Notifies the native side that the printing process is completed. This method should be
-     * called when the process was initiated by the native side (window.print())
-     */
-    void showSystemDialogDone();
 }

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

@@ -77,7 +77,7 @@ public interface PrintingController {
 
     /**
      * Sets the data required to initiate a printing process. The process can later be started using
-     * {@link #startPendingPrint(PrintingContextInterface)}.
+     * {@link #startPendingPrint()}.
      *
      * @param printable An object capable of starting native side PDF generation, i.e. typically
      *     a Tab.
@@ -92,11 +92,6 @@ public interface PrintingController {
     /**
      * Starts printing, provided that the current object already has sufficient data to start the
      * process. (using {@link #setPendingPrint(Printable, PrintManagerDelegate)} for example)
-     *
-     * @param jsOriginatedPrintingContext The printingContext holding the callback to be used to
-     *     reply when javascript can resume. When printing is done (or could not start),
-     *     {@link PrintingContextInterface#showSystemDialogDone()} will be called on this object.
      */
-    void startPendingPrint(PrintingContextInterface jsOriginatedPrintingContext);
-
+    void startPendingPrint();
 }

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

@@ -51,11 +51,6 @@ public class PrintingControllerImpl implements PrintingController, PdfGenerator
 
     private PrintingContextInterface mPrintingContext;
 
-    /**
-     * The context of a query initiated by window.print(), stored here to allow syncrhonization
-     * with javascript.
-     */
-    private PrintingContextInterface mContextFromScriptInitiation;
     private int mRenderProcessId;
     private int mRenderFrameId;
 
@@ -190,7 +185,7 @@ public class PrintingControllerImpl implements PrintingController, PdfGenerator
     }
 
     @Override
-    public void startPendingPrint(PrintingContextInterface printingContext) {
+    public void startPendingPrint() {
         boolean canStartPrint = false;
         if (mIsBusy) {
             Log.d(TAG, "Pending print can't be started. PrintingController is busy.");
@@ -202,12 +197,8 @@ public class PrintingControllerImpl implements PrintingController, PdfGenerator
             canStartPrint = true;
         }
 
-        if (!canStartPrint) {
-            if (printingContext != null) printingContext.showSystemDialogDone();
-            return;
-        }
+        if (!canStartPrint) return;
 
-        mContextFromScriptInitiation = printingContext;
         mIsBusy = true;
         mPrintDocumentAdapterWrapper.print(mPrintManager, mPrintable.getTitle());
         mPrintManager = null;
@@ -217,7 +208,7 @@ public class PrintingControllerImpl implements PrintingController, PdfGenerator
     public void startPrint(final Printable printable, PrintManagerDelegate printManager) {
         if (mIsBusy) return;
         setPendingPrint(printable, printManager, mRenderProcessId, mRenderFrameId);
-        startPendingPrint(null);
+        startPendingPrint();
     }
 
     @Override
@@ -313,10 +304,6 @@ public class PrintingControllerImpl implements PrintingController, PdfGenerator
             mPrintingContext = null;
         }
 
-        if (mContextFromScriptInitiation != null) {
-            mContextFromScriptInitiation.showSystemDialogDone();
-            mContextFromScriptInitiation = null;
-        }
         mRenderProcessId = -1;
         mRenderFrameId = -1;