Preserve original on redirect with the set-cookie flow.

We need to make sure the original header is retained when we redirect.

I filed a request on Cronet to allow headers to be provided to the UrlRequest#followRedirect method:
https://bugs.chromium.org/p/chromium/issues/detail?id=779611

Until that API is changed, i.e., pulled into GMSCore, and most clients are using the version of GMSCore with the API change, we can stick with this approach.

FYI

Cronet generally uses the original headers on redirect:

http://[]

but modifies the headers for these special cases:

hhttp://[]

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=174074572

extensions/cronet/src/androidTest/java/com/google/android/exoplayer2/ext/cronet/CronetDataSourceTest.java

@@ -714,7 +714,7 @@ public final class CronetDataSourceTest {
   }
   }
 
 
   @Test
   @Test
-  public void testRedirectParseAndAttachCookie_dataSourceHandlesSetCookie()
+  public void testRedirectParseAndAttachCookie_dataSourceHandlesSetCookie_andPreservesOriginalRequestHeaders()
       throws HttpDataSourceException {
       throws HttpDataSourceException {
     dataSourceUnderTest = spy(
     dataSourceUnderTest = spy(
         new CronetDataSource(
         new CronetDataSource(
@@ -728,12 +728,46 @@ public final class CronetDataSourceTest {
             mockClock,
             mockClock,
             null,
             null,
             true));
             true));
+    dataSourceUnderTest.setRequestProperty("Content-Type", TEST_CONTENT_TYPE);
+
+    mockSingleRedirectSuccess();
+
+    testResponseHeader.put("Set-Cookie", "testcookie=testcookie; Path=/video");
+
+    dataSourceUnderTest.open(testDataSpec);
+    verify(mockUrlRequestBuilder).addHeader(eq("Cookie"), any(String.class));
+    verify(mockUrlRequestBuilder, never()).addHeader(eq("Range"), any(String.class));
+    verify(mockUrlRequestBuilder, times(2)).addHeader("Content-Type", TEST_CONTENT_TYPE);
+    verify(mockUrlRequest, never()).followRedirect();
+    verify(mockUrlRequest, times(2)).start();
+  }
+
+  @Test
+  public void testRedirectParseAndAttachCookie_dataSourceHandlesSetCookie_andPreservesOriginalRequestHeadersIncludingByteRangeHeader()
+      throws HttpDataSourceException {
+    testDataSpec = new DataSpec(Uri.parse(TEST_URL), 1000, 5000, null);
+    dataSourceUnderTest = spy(
+        new CronetDataSource(
+            mockCronetEngine,
+            mockExecutor,
+            mockContentTypePredicate,
+            mockTransferListener,
+            TEST_CONNECT_TIMEOUT_MS,
+            TEST_READ_TIMEOUT_MS,
+            true, // resetTimeoutOnRedirects
+            mockClock,
+            null,
+            true));
+    dataSourceUnderTest.setRequestProperty("Content-Type", TEST_CONTENT_TYPE);
+
     mockSingleRedirectSuccess();
     mockSingleRedirectSuccess();
 
 
     testResponseHeader.put("Set-Cookie", "testcookie=testcookie; Path=/video");
     testResponseHeader.put("Set-Cookie", "testcookie=testcookie; Path=/video");
 
 
     dataSourceUnderTest.open(testDataSpec);
     dataSourceUnderTest.open(testDataSpec);
     verify(mockUrlRequestBuilder).addHeader(eq("Cookie"), any(String.class));
     verify(mockUrlRequestBuilder).addHeader(eq("Cookie"), any(String.class));
+    verify(mockUrlRequestBuilder, times(2)).addHeader("Range", "bytes=1000-5999");
+    verify(mockUrlRequestBuilder, times(2)).addHeader("Content-Type", TEST_CONTENT_TYPE);
     verify(mockUrlRequest, never()).followRedirect();
     verify(mockUrlRequest, never()).followRedirect();
     verify(mockUrlRequest, times(2)).start();
     verify(mockUrlRequest, times(2)).start();
   }
   }

extensions/cronet/src/main/java/com/google/android/exoplayer2/ext/cronet/CronetDataSource.java

@@ -263,7 +263,11 @@ public class CronetDataSource extends UrlRequest.Callback implements HttpDataSou
     operation.close();
     operation.close();
     resetConnectTimeout();
     resetConnectTimeout();
     currentDataSpec = dataSpec;
     currentDataSpec = dataSpec;
-    currentUrlRequest = buildRequest(dataSpec);
+    try {
+      currentUrlRequest = buildRequestBuilder(dataSpec).build();
+    } catch (IOException e) {
+      throw new OpenException(e, currentDataSpec, Status.IDLE);
+    }
     currentUrlRequest.start();
     currentUrlRequest.start();
 
 
     try {
     try {
@@ -439,9 +443,18 @@ public class CronetDataSource extends UrlRequest.Callback implements HttpDataSou
     if (!handleSetCookieRequests || isEmpty(headers.get(SET_COOKIE))) {
     if (!handleSetCookieRequests || isEmpty(headers.get(SET_COOKIE))) {
       request.followRedirect();
       request.followRedirect();
     } else {
     } else {
-      UrlRequest.Builder requestBuilder =
-          cronetEngine.newUrlRequestBuilder(newLocationUrl, /* callback= */ this, executor);
       currentUrlRequest.cancel();
       currentUrlRequest.cancel();
+      DataSpec redirectUrlDataSpec = new DataSpec(Uri.parse(newLocationUrl),
+          currentDataSpec.postBody, currentDataSpec.absoluteStreamPosition,
+          currentDataSpec.position, currentDataSpec.length, currentDataSpec.key,
+          currentDataSpec.flags);
+      UrlRequest.Builder requestBuilder;
+      try {
+        requestBuilder = buildRequestBuilder(redirectUrlDataSpec);
+      } catch (IOException e) {
+        exception = e;
+        return;
+      }
       String cookieHeadersValue = parseCookies(headers.get(SET_COOKIE));
       String cookieHeadersValue = parseCookies(headers.get(SET_COOKIE));
       attachCookies(requestBuilder, cookieHeadersValue);
       attachCookies(requestBuilder, cookieHeadersValue);
       currentUrlRequest = requestBuilder.build();
       currentUrlRequest = requestBuilder.build();
@@ -494,7 +507,7 @@ public class CronetDataSource extends UrlRequest.Callback implements HttpDataSou
 
 
   // Internal methods.
   // Internal methods.
 
 
-  private UrlRequest buildRequest(DataSpec dataSpec) throws OpenException {
+  private UrlRequest.Builder buildRequestBuilder(DataSpec dataSpec) throws IOException {
     UrlRequest.Builder requestBuilder = cronetEngine.newUrlRequestBuilder(
     UrlRequest.Builder requestBuilder = cronetEngine.newUrlRequestBuilder(
         dataSpec.uri.toString(), this, executor).allowDirectExecutor();
         dataSpec.uri.toString(), this, executor).allowDirectExecutor();
     // Set the headers.
     // Set the headers.
@@ -513,17 +526,16 @@ public class CronetDataSource extends UrlRequest.Callback implements HttpDataSou
       requestBuilder.addHeader(key, headerEntry.getValue());
       requestBuilder.addHeader(key, headerEntry.getValue());
     }
     }
     if (dataSpec.postBody != null && dataSpec.postBody.length != 0 && !isContentTypeHeaderSet) {
     if (dataSpec.postBody != null && dataSpec.postBody.length != 0 && !isContentTypeHeaderSet) {
-      throw new OpenException("POST request with non-empty body must set Content-Type", dataSpec,
-          Status.IDLE);
+      throw new IOException("POST request with non-empty body must set Content-Type");
     }
     }
     // Set the Range header.
     // Set the Range header.
-    if (currentDataSpec.position != 0 || currentDataSpec.length != C.LENGTH_UNSET) {
+    if (dataSpec.position != 0 || dataSpec.length != C.LENGTH_UNSET) {
       StringBuilder rangeValue = new StringBuilder();
       StringBuilder rangeValue = new StringBuilder();
       rangeValue.append("bytes=");
       rangeValue.append("bytes=");
-      rangeValue.append(currentDataSpec.position);
+      rangeValue.append(dataSpec.position);
       rangeValue.append("-");
       rangeValue.append("-");
-      if (currentDataSpec.length != C.LENGTH_UNSET) {
-        rangeValue.append(currentDataSpec.position + currentDataSpec.length - 1);
+      if (dataSpec.length != C.LENGTH_UNSET) {
+        rangeValue.append(dataSpec.position + dataSpec.length - 1);
       }
       }
       requestBuilder.addHeader("Range", rangeValue.toString());
       requestBuilder.addHeader("Range", rangeValue.toString());
     }
     }
@@ -541,7 +553,7 @@ public class CronetDataSource extends UrlRequest.Callback implements HttpDataSou
             executor);
             executor);
       }
       }
     }
     }
-    return requestBuilder.build();
+    return requestBuilder;
   }
   }
 
 
   private boolean blockUntilConnectTimeout() throws InterruptedException {
   private boolean blockUntilConnectTimeout() throws InterruptedException {