Build dynamic iOS SDK.

webrtc/build/ios/SDK/README

-We want to generate a dynamic framework for a CocoaPod. Unfortunately, using gyp-xcode generation
-for a framework currently presents some issues. To get around those issues, we chose to create a
-project with Xcode for building the framework directly.
-
-The Framework directory contains the Xcode project used to build the framework. The PodTest
-directory contains a project used to confirm that the built framework installs correctly with
-CocoaPods. The build_ios_framework.sh script needs to be run first, then `pod install` should be run
-in the same directory as the Xcode project. After installing, the PodTest.xcworkspace should be used
-instead of PodTest.xcodeproj.
-
-USAGE
-To build the framework, run the build_ios_framework.sh script. This will build static libraries for
-iOS (via the build_ios_libs.sh script), collect header files and adjust import/include statements
-for use inside the framework, build the framework using the Xcode project, merge multiple
-architectures together, and collect the framework files (the .framework itself and the .dSYM) with
-the Podspec into a common directory.
-
-DETAILS OF THE XCODE PROJECT
-The Xcode project contains relative references to the built static libraries (from
-build_ios_libs.sh), with the exception of librtc_api_objc and librtc_base_objc. The iOS source files
-from webrtc/api/objc and webrtc/base/objc are also included. NOTE: This will require updating
-if/when the built static libraries change.
-
-The flattened header files for webrtc/api/objc and webrtc/base/objc were also added to the Public
-Headers of the framework target. NOTE: This will require updating as the Obj-C API changes.
-
-Preprocessor definitions were copied from a gyp-xcode generated project.
-
-RTTI was disabled due to compiler errors and based on the setting in build/common.gypi
-(https://code.google.com/p/chromium/codesearch#chromium/src/build/common.gypi&q=rtti&sq=package:chromium&type=cs&l=5069).
-
-Bitcode is disabled for the time being.
-
-The minimum number of system frameworks were linked against based on build errors (currently
-AVFoundation, AudioToolbox, CoreMedia, VideoToolbox).
-
-The Build Products Path (SYMROOT) was changed to $SRCROOT/build so the build products are in a known
-location.
-
-The created WebRTC scheme was shared so the build_ios_framework.sh script will work on any machine
-that runs it.
-
-DEPLOYMENT_POSTPROCESSING is set to "Yes" so debug symbols will be stripped (the iOS Default for
-STRIP_INSTALLED_PRODUCT is already set to "Yes").
-
-"-ObjC" is added to OTHER_LDFLAGS to ensure category methods (in particular, those from
-RTCAudioSession+Configuration.mm) are included in the framework binary.
-
-During the build process, dSYMs will be generated for each architecture alongside each framework
-bundle. These are merged together and placed alongside the final framework product.