Bug 1546744 - Ensure we are testing for the correct things when valid…

…ating screenshots r=eeejay

Differential Revision: https://phabricator.services.mozilla.com/D28983

mobile/android/geckoview/src/androidTest/java/org/mozilla/geckoview/test/ScreenshotTest.kt

@@ -9,8 +9,7 @@ import android.graphics.*
 import android.support.test.filters.MediumTest
 import android.support.test.runner.AndroidJUnit4
 import android.view.Surface
-import org.hamcrest.Matchers.notNullValue
-import org.hamcrest.Matchers.nullValue
+import org.hamcrest.Matchers.*
 import org.junit.Assert.fail
 import org.junit.Rule
 import org.junit.Test
@@ -19,6 +18,7 @@ import org.junit.runner.RunWith
 import org.mozilla.geckoview.GeckoResult
 import org.mozilla.geckoview.test.rule.GeckoSessionTestRule.ReuseSession
 import org.mozilla.geckoview.test.rule.GeckoSessionTestRule.WithDisplay
+import java.nio.ByteBuffer
 
 private const val SCREEN_HEIGHT = 100
 private const val SCREEN_WIDTH = 100
@@ -44,7 +44,15 @@ class ScreenshotTest : BaseSessionTest() {
         sessionRule.waitForResult(result).let {
             assertThat("Screenshot is not null",
                     it, notNullValue())
-            assert(it.sameAs(comparisonImage)) {  "Screenshots are the same" }
+            assertThat("Widths are the same", comparisonImage.width, equalTo(it.width))
+            assertThat("Heights are the same", comparisonImage.height, equalTo(it.height))
+            assertThat("Byte counts are the same", comparisonImage.byteCount, equalTo(it.byteCount))
+            assertThat("Configs are the same", comparisonImage.config, equalTo(it.config))
+            val comparisonPixels: ByteBuffer = ByteBuffer.allocate(comparisonImage.byteCount)
+            comparisonImage.copyPixelsToBuffer(comparisonPixels)
+            val itPixels: ByteBuffer = ByteBuffer.allocate(it.byteCount)
+            it.copyPixelsToBuffer(itPixels)
+            assertThat("Bytes are the same", comparisonPixels, equalTo(itPixels))
         }
     }