Use sequence numbers to synchronize enabling Pointer Capture (1/2)

InputReader only processes configuration change from its main thread.
This means that if there is more than one Pointer Capture change
request when the thread is busy or sleeping, it will only process the
latest one. To ensure requests to enable Pointer Capture are synchronized
with Dispatcher, we must use sequence numbers.

Requests to enable Pointer Capture have a sequence number. Requests to
disable Pointer Capture do not have a value.

Bug: 195312888
Test: atest inputflinger_tests
Test: manual with GeforceNow app, see bug.
Change-Id: I6ae9c5498dc2f783b4c7211fa3665d42e29d2919
diff --git a/services/inputflinger/tests/InputReader_test.cpp b/services/inputflinger/tests/InputReader_test.cpp
index c76ed38..91d246a 100644
--- a/services/inputflinger/tests/InputReader_test.cpp
+++ b/services/inputflinger/tests/InputReader_test.cpp
@@ -312,8 +312,9 @@
         transform = t;
     }
 
-    void setPointerCapture(bool enabled) {
-        mConfig.pointerCapture = enabled;
+    PointerCaptureRequest setPointerCapture(bool enabled) {
+        mConfig.pointerCaptureRequest = {enabled, mNextPointerCaptureSequenceNumber++};
+        return mConfig.pointerCaptureRequest;
     }
 
     void setShowTouches(bool enabled) {
@@ -327,6 +328,8 @@
     float getPointerGestureMovementSpeedRatio() { return mConfig.pointerGestureMovementSpeedRatio; }
 
 private:
+    uint32_t mNextPointerCaptureSequenceNumber = 0;
+
     DisplayViewport createDisplayViewport(int32_t displayId, int32_t width, int32_t height,
                                           int32_t orientation, bool isActive,
                                           const std::string& uniqueId,
@@ -1993,24 +1996,24 @@
 TEST_F(InputReaderTest, ChangingPointerCaptureNotifiesInputListener) {
     NotifyPointerCaptureChangedArgs args;
 
-    mFakePolicy->setPointerCapture(true);
+    auto request = mFakePolicy->setPointerCapture(true);
     mReader->requestRefreshConfiguration(InputReaderConfiguration::CHANGE_POINTER_CAPTURE);
     mReader->loopOnce();
     mFakeListener->assertNotifyCaptureWasCalled(&args);
-    ASSERT_TRUE(args.enabled) << "Pointer Capture should be enabled.";
+    ASSERT_TRUE(args.request.enable) << "Pointer Capture should be enabled.";
+    ASSERT_EQ(args.request, request) << "Pointer Capture sequence number should match.";
 
     mFakePolicy->setPointerCapture(false);
     mReader->requestRefreshConfiguration(InputReaderConfiguration::CHANGE_POINTER_CAPTURE);
     mReader->loopOnce();
     mFakeListener->assertNotifyCaptureWasCalled(&args);
-    ASSERT_FALSE(args.enabled) << "Pointer Capture should be disabled.";
+    ASSERT_FALSE(args.request.enable) << "Pointer Capture should be disabled.";
 
-    // Verify that the Pointer Capture state is re-configured correctly when the configuration value
+    // Verify that the Pointer Capture state is not updated when the configuration value
     // does not change.
     mReader->requestRefreshConfiguration(InputReaderConfiguration::CHANGE_POINTER_CAPTURE);
     mReader->loopOnce();
-    mFakeListener->assertNotifyCaptureWasCalled(&args);
-    ASSERT_FALSE(args.enabled) << "Pointer Capture should be disabled.";
+    mFakeListener->assertNotifyCaptureWasNotCalled();
 }
 
 class FakeVibratorInputMapper : public FakeInputMapper {