Cronet iOS: Delete CRNPauseableHTTPProtocolHandler

BUG=711783
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_cronet_tester

Review-Url: https://codereview.chromium.org/2856693002
Cr-Commit-Position: refs/heads/master@{#468639}

components/cronet/ios/Cronet.mm

@@ -260,7 +260,7 @@ class CronetHttpProtocolHandlerDelegate
   [NSURLCache setSharedURLCache:[EmptyNSURLCache emptyNSURLCache]];
   // Register the chrome http protocol handler to replace the default one.
   BOOL success =
-      [NSURLProtocol registerClass:[CRNPauseableHTTPProtocolHandler class]];
+      [NSURLProtocol registerClass:[CRNHTTPProtocolHandler class]];
   DCHECK(success);
 }
 
@@ -270,11 +270,11 @@ class CronetHttpProtocolHandlerDelegate
     [NSURLCache setSharedURLCache:gPreservedSharedURLCache];
     gPreservedSharedURLCache = nil;
   }
-  [NSURLProtocol unregisterClass:[CRNPauseableHTTPProtocolHandler class]];
+  [NSURLProtocol unregisterClass:[CRNHTTPProtocolHandler class]];
 }
 
 + (void)installIntoSessionConfiguration:(NSURLSessionConfiguration*)config {
-  config.protocolClasses = @[ [CRNPauseableHTTPProtocolHandler class] ];
+  config.protocolClasses = @[ [CRNHTTPProtocolHandler class] ];
 }
 
 + (NSString*)getNetLogPathForFile:(NSString*)fileName {

ios/crnet/crnet_environment.mm

@@ -311,7 +311,7 @@ void CrNetEnvironment::Install() {
 
 void CrNetEnvironment::InstallIntoSessionConfiguration(
     NSURLSessionConfiguration* config) {
-  config.protocolClasses = @[ [CRNPauseableHTTPProtocolHandler class] ];
+  config.protocolClasses = @[ [CRNHTTPProtocolHandler class] ];
 }
 
 CrNetEnvironment::~CrNetEnvironment() {
@@ -328,14 +328,14 @@ void CrNetEnvironment::SetHTTPProtocolHandlerRegistered(bool registered) {
     [NSURLCache setSharedURLCache:[EmptyNSURLCache emptyNSURLCache]];
     // Register the chrome http protocol handler to replace the default one.
     BOOL success =
-        [NSURLProtocol registerClass:[CRNPauseableHTTPProtocolHandler class]];
+        [NSURLProtocol registerClass:[CRNHTTPProtocolHandler class]];
     DCHECK(success);
   } else {
     // Set up an empty default cache, with default size.
     // TODO(droger): If the NSURLCache is to be used, its size should most
     // likely be changed. On an iPod2 with iOS4, the default size is 512k.
     [NSURLCache setSharedURLCache:[[[NSURLCache alloc] init] autorelease]];
-    [NSURLProtocol unregisterClass:[CRNPauseableHTTPProtocolHandler class]];
+    [NSURLProtocol unregisterClass:[CRNHTTPProtocolHandler class]];
   }
 }
 

ios/net/crn_http_protocol_handler.h

@@ -40,13 +40,4 @@ class HTTPProtocolHandlerDelegate {
 @interface CRNHTTPProtocolHandler : NSURLProtocol
 @end
 
-// Custom NSURLProtocol handling HTTP and HTTPS requests.
-// The HttpProtocolHandler is registered as a NSURLProtocol in the iOS system.
-// This protocol is called for each NSURLRequest. This allows handling the
-// requests issued by UIWebView using our own network stack. This protocol
-// handler implements iOS 8 NSURLProtocol pause/resume semantics, in which
-// |startLoading| means "start or resume" and |stopLoading| means "pause".
-@interface CRNPauseableHTTPProtocolHandler : CRNHTTPProtocolHandler
-@end
-
 #endif  // IOS_NET_CRN_HTTP_PROTOCOL_HANDLER_H_

ios/net/crn_http_protocol_handler.mm

@@ -965,77 +965,3 @@ void HttpProtocolHandlerCore::StripPostSpecificHeaders(
 }
 
 @end
-
-#pragma mark -
-#pragma mark PauseableHttpProtocolHandler
-
-// The HttpProtocolHandler is called by the iOS system to handle the
-// NSURLRequest. This HttpProtocolHandler conforms to the observed semantics of
-// NSURLProtocol when used with NSURLSession on iOS 8 - i.e., |-startLoading|
-// means "start or resume request" and |-stopLoading| means "pause request".
-// Since there is no way to actually pause a request in the network stack, this
-// is implemented using a subclass of CRNHTTPProtocolHandlerProxy that knows how
-// to defer callbacks.
-//
-// Note that this class conforms to somewhat complex threading rules:
-// 1) |initWithRequest:cachedResponse:client:| and |dealloc| can be called on
-//    any thread.
-// 2) |startLoading| and |stopLoading| are always called on the client thread.
-// 3) |stopLoading| is called before |dealloc| is called.
-//
-// The main wrinkle is that |dealloc|, which may be called on any thread, needs
-// to clean up a running network request. To do this, |dealloc| needs to run
-// |cancelRequest|, which needs to be run on the client thread. Since it is
-// guaranteed that |startLoading| is called before |dealloc| is called, the
-// |startLoading| method stores a pointer to the client thread, then |dealloc|
-// asks that client thread to perform the |cancelRequest| selector via
-// |scheduleCancelRequest|.
-//
-// Some of the above logic is implemented in the parent class
-// (CRNHTTPProtocolHandler) because it is convenient.
-@implementation CRNPauseableHTTPProtocolHandler {
-  BOOL _started;
-  dispatch_queue_t _queue;
-}
-
-#pragma mark NSURLProtocol methods
-
-- (void)dealloc {
-  [self scheduleCancelRequest];
-}
-
-#pragma mark NSURLProtocol overrides.
-
-- (void)startLoading {
-  if (_started) {
-    [[self getProtocolHandlerProxy] resume];
-    return;
-  }
-
-  _started = YES;
-  [super startLoading];
-}
-
-- (void)stopLoading {
-  [[self getProtocolHandlerProxy] pause];
-}
-
-// This method has unusual concurrency properties. It can be called on any
-// thread, but it must be called from |-dealloc|, which guarantees that no other
-// method of this object is running concurrently (since |-dealloc| is only
-// called when the last reference to the object drops).
-//
-// This method takes a reference to _core to ensure that _core lives long enough
-// to have the request cleanly cancelled.
-- (void)scheduleCancelRequest {
-  DeferredCancellation* cancellation =
-      [[DeferredCancellation alloc] initWithCore:[self getCore]];
-  NSArray* modes = @[ [[NSRunLoop currentRunLoop] currentMode] ];
-  [cancellation performSelector:@selector(cancel)
-                       onThread:[self getClientThread]
-                     withObject:nil
-                  waitUntilDone:NO
-                          modes:modes];
-}
-
-@end