[Cronet] Integrate CrNet functionality into Cronet on iOS.

components/cronet/ios/Cronet.h

Index: components/cronet/ios/Cronet.h
diff --git a/components/cronet/ios/Cronet.h b/components/cronet/ios/Cronet.h
index fc7b9c2486aa0573c1e3ce33264b8a67646e7390..d5be3eaa119968ece40300273acead10f4f91468 100644
--- a/components/cronet/ios/Cronet.h
+++ b/components/cronet/ios/Cronet.h
@@ -6,6 +6,10 @@
 
 #include "cronet_c_for_grpc.h"
 
+// A block, that takes a request, and returns YES if the request should
+// be handled.
+typedef BOOL (^RequestFilterBlock)(NSURLRequest* request);
+
 // Interface for installing Cronet.
 CRONET_EXPORT
 @interface Cronet : NSObject
@@ -32,6 +36,11 @@ CRONET_EXPORT
 // captures. This method only has any effect before |start| is called.
 + (void)setSslKeyLogFileName:(NSString*)sslKeyLogFileName;
 
+// Set the block used to determine whether or not Cronet should handle the
+// request. If this is not set, Cronet will handle all requests.
+// This method only has any effect before |start| is called.
++ (void)setRequestFilterBlock:(RequestFilterBlock)block;

[kapishnikov, 2016/08/12 17:19:31]

We should mention in the doc whether the method keeps the strong or weak
reference to the block. 

[mef, 2016/08/26 14:58:07]

Done. Changed it to reset block after start, so it could be released.

+
 // Starts CronetEngine. It is recommended to call this method on the application
 // main thread. If the method is called on any thread other than the main one,
 // the method will internally try to execute synchronously using the main GCD
@@ -39,6 +48,25 @@ CRONET_EXPORT
 // that calls this method; otherwise, a deadlock can occur.
 + (void)start;
 
+// Registers Cronet as HttpProtocol Handler. Once registered, Cronet intercepts
+// and handles all NSURLConnection and NSURLRequests issued by the app,
+// including requests done through shared NSURLSession.
+// This method must be called after |start|.
++ (void)registerHttpProtocolHandler;
+
+// Unregister Cronet as HttpProtocol Handler. This means that Cronet will stop
+// intercepting requests, however, it won't tear down the Cronet environment.
+// This method must be called after |start|.
++ (void)unregisterHttpProtocolHandler;
+
+// Installs Cronet into Cronet into NSURLSessionConfiguration so that all

[kapishnikov, 2016/08/12 17:19:31]

Remove repeating "Cronet into"

[mef, 2016/08/26 14:58:07]

Done.

+// NSURLSessions created with this configuration will use the Cronet stack.
+// Note that this NSURLSession will share Cronet settings with the

[kapishnikov, 2016/08/12 17:19:31]

Maybe we should mention that Cronet settings are global and are shared between
all NSURLSessions & NSURLConnections that use the Cronet stack.

[mef, 2016/08/26 14:58:07]

Done.

+// sharedSession,
+// which the |registerHttpProtocolHandler| method installs Cronet into.
+// This method must be called after |start|.
++ (void)installIntoSessionConfiguration:(NSURLSessionConfiguration*)config;
+
 // Starts net-internals logging to a file named |fileName| in the application
 // temporary directory. |fileName| must not be empty. Log level is determined
 // by |logBytes| - if YES then LOG_ALL otherwise LOG_ALL_BUT_BYTES. If the file
@@ -57,4 +85,14 @@ CRONET_EXPORT
 // Get a pointer to global instance of cronet_engine for GRPC C API.
 + (cronet_engine*)getGlobalEngine;
 
+// Returns differences in metrics collected by Cronet since the last call to
+// getGlobalMetricsDeltas, serialized as a
+// <a href=https://developers.google.com/protocol-buffers>protobuf</a>.
+//
+// Cronet starts collecting these metrics after the first call to
+// getGlobalMetricsDeltras, so the first call returns no
+// useful data as no metrics have yet been collected.
+// differences in metrics collected by Cronet, since the last call
++ (NSData*)getGlobalMetricsDeltas;
+
 @end