[darwin] Simplify MGLStyleLayer initialization and pointer management

Similarly to the previous commit, introduce `-[MGLStyleLayer initWithPendingLayer:]`, allowing the base class to track the owned `_pendingSource` pointer and implement `-addToMapView:` and `-removeFromMapView:` without any casts.

Fixes an issue where `-[MGLStyle layerFromMBGLLayer:]` would wind up creating layers whose `_rawLayer` and `_pendingLayer` held different values.

1 files changed, 12 insertions, 6 deletions

diff --git a/platform/ios/ios.xcodeproj/project.pbxproj b/platform/ios/ios.xcodeproj/project.pbxproj
index 2f16e29618..a9e69f836e 100644
--- a/platform/ios/ios.xcodeproj/project.pbxproj
+++ b/platform/ios/ios.xcodeproj/project.pbxproj
@@ -53,8 +53,8 @@
 		35305D4A1D22AA6A0007D005 /* NSData+MGLAdditions.h in Headers */ = {isa = PBXBuildFile; fileRef = 35305D461D22AA450007D005 /* NSData+MGLAdditions.h */; };
 		3538AA1D1D542239008EC33D /* MGLForegroundStyleLayer.h in Headers */ = {isa = PBXBuildFile; fileRef = 3538AA1B1D542239008EC33D /* MGLForegroundStyleLayer.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		3538AA1E1D542239008EC33D /* MGLForegroundStyleLayer.h in Headers */ = {isa = PBXBuildFile; fileRef = 3538AA1B1D542239008EC33D /* MGLForegroundStyleLayer.h */; settings = {ATTRIBUTES = (Public, ); }; };
-		3538AA1F1D542239008EC33D /* MGLForegroundStyleLayer.m in Sources */ = {isa = PBXBuildFile; fileRef = 3538AA1C1D542239008EC33D /* MGLForegroundStyleLayer.m */; };
-		3538AA201D542239008EC33D /* MGLForegroundStyleLayer.m in Sources */ = {isa = PBXBuildFile; fileRef = 3538AA1C1D542239008EC33D /* MGLForegroundStyleLayer.m */; };
+		3538AA1F1D542239008EC33D /* MGLForegroundStyleLayer.mm in Sources */ = {isa = PBXBuildFile; fileRef = 3538AA1C1D542239008EC33D /* MGLForegroundStyleLayer.mm */; };
+		3538AA201D542239008EC33D /* MGLForegroundStyleLayer.mm in Sources */ = {isa = PBXBuildFile; fileRef = 3538AA1C1D542239008EC33D /* MGLForegroundStyleLayer.mm */; };
 		353933F21D3FB753003F57D7 /* MGLCircleStyleLayer.h in Headers */ = {isa = PBXBuildFile; fileRef = 353933F11D3FB753003F57D7 /* MGLCircleStyleLayer.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		353933F31D3FB753003F57D7 /* MGLCircleStyleLayer.h in Headers */ = {isa = PBXBuildFile; fileRef = 353933F11D3FB753003F57D7 /* MGLCircleStyleLayer.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		353933F51D3FB785003F57D7 /* MGLBackgroundStyleLayer.h in Headers */ = {isa = PBXBuildFile; fileRef = 353933F41D3FB785003F57D7 /* MGLBackgroundStyleLayer.h */; settings = {ATTRIBUTES = (Public, ); }; };
@@ -168,6 +168,8 @@
 		40F887701D7A1E58008ECB67 /* MGLShapeSource_Private.h in Headers */ = {isa = PBXBuildFile; fileRef = 40F8876F1D7A1DB8008ECB67 /* MGLShapeSource_Private.h */; };
 		40F887711D7A1E59008ECB67 /* MGLShapeSource_Private.h in Headers */ = {isa = PBXBuildFile; fileRef = 40F8876F1D7A1DB8008ECB67 /* MGLShapeSource_Private.h */; };
 		40FDA76B1CCAAA6800442548 /* MBXAnnotationView.m in Sources */ = {isa = PBXBuildFile; fileRef = 40FDA76A1CCAAA6800442548 /* MBXAnnotationView.m */; };
+		522ADA011E955C2F00096484 /* MGLForegroundStyleLayer_Private.h in Headers */ = {isa = PBXBuildFile; fileRef = 522ADA001E955C2300096484 /* MGLForegroundStyleLayer_Private.h */; };
+		522ADA021E955C3000096484 /* MGLForegroundStyleLayer_Private.h in Headers */ = {isa = PBXBuildFile; fileRef = 522ADA001E955C2300096484 /* MGLForegroundStyleLayer_Private.h */; };
 		556660CA1E1BF3A900E2C41B /* MGLFoundation.h in Headers */ = {isa = PBXBuildFile; fileRef = 556660C91E1BF3A900E2C41B /* MGLFoundation.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		556660D81E1D085500E2C41B /* MGLVersionNumber.m in Sources */ = {isa = PBXBuildFile; fileRef = 556660D71E1D085500E2C41B /* MGLVersionNumber.m */; };
 		556660DB1E1D8E8D00E2C41B /* MGLFoundation.h in Headers */ = {isa = PBXBuildFile; fileRef = 556660C91E1BF3A900E2C41B /* MGLFoundation.h */; settings = {ATTRIBUTES = (Public, ); }; };
@@ -556,7 +558,7 @@
 		35305D461D22AA450007D005 /* NSData+MGLAdditions.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "NSData+MGLAdditions.h"; sourceTree = "<group>"; };
 		35305D471D22AA450007D005 /* NSData+MGLAdditions.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = "NSData+MGLAdditions.mm"; sourceTree = "<group>"; };
 		3538AA1B1D542239008EC33D /* MGLForegroundStyleLayer.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MGLForegroundStyleLayer.h; sourceTree = "<group>"; };
-		3538AA1C1D542239008EC33D /* MGLForegroundStyleLayer.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MGLForegroundStyleLayer.m; sourceTree = "<group>"; };
+		3538AA1C1D542239008EC33D /* MGLForegroundStyleLayer.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = MGLForegroundStyleLayer.mm; sourceTree = "<group>"; };
 		353933F11D3FB753003F57D7 /* MGLCircleStyleLayer.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MGLCircleStyleLayer.h; sourceTree = "<group>"; };
 		353933F41D3FB785003F57D7 /* MGLBackgroundStyleLayer.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MGLBackgroundStyleLayer.h; sourceTree = "<group>"; };
 		353933F71D3FB79F003F57D7 /* MGLLineStyleLayer.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MGLLineStyleLayer.h; sourceTree = "<group>"; };
@@ -632,6 +634,7 @@
 		40F8876F1D7A1DB8008ECB67 /* MGLShapeSource_Private.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = MGLShapeSource_Private.h; sourceTree = "<group>"; };
 		40FDA7691CCAAA6800442548 /* MBXAnnotationView.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MBXAnnotationView.h; sourceTree = "<group>"; };
 		40FDA76A1CCAAA6800442548 /* MBXAnnotationView.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MBXAnnotationView.m; sourceTree = "<group>"; };
+		522ADA001E955C2300096484 /* MGLForegroundStyleLayer_Private.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MGLForegroundStyleLayer_Private.h; sourceTree = "<group>"; };
 		554180411D2E97DE00012372 /* OpenGLES.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = OpenGLES.framework; path = System/Library/Frameworks/OpenGLES.framework; sourceTree = SDKROOT; };
 		556660C91E1BF3A900E2C41B /* MGLFoundation.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = MGLFoundation.h; sourceTree = "<group>"; };
 		556660D71E1D085500E2C41B /* MGLVersionNumber.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; name = MGLVersionNumber.m; path = ../../darwin/test/MGLVersionNumber.m; sourceTree = "<group>"; };
@@ -976,6 +979,7 @@
 		353933F01D3FB6BA003F57D7 /* Layers */ = {
 			isa = PBXGroup;
 			children = (
+				522ADA001E955C2300096484 /* MGLForegroundStyleLayer_Private.h */,
 				353933F41D3FB785003F57D7 /* MGLBackgroundStyleLayer.h */,
 				35136D381D42271A00C20EFD /* MGLBackgroundStyleLayer.mm */,
 				353933F11D3FB753003F57D7 /* MGLCircleStyleLayer.h */,
@@ -983,7 +987,7 @@
 				35D13AC11D3D19DD00AFB4E0 /* MGLFillStyleLayer.h */,
 				35D13AC21D3D19DD00AFB4E0 /* MGLFillStyleLayer.mm */,
 				3538AA1B1D542239008EC33D /* MGLForegroundStyleLayer.h */,
-				3538AA1C1D542239008EC33D /* MGLForegroundStyleLayer.m */,
+				3538AA1C1D542239008EC33D /* MGLForegroundStyleLayer.mm */,
 				353933F71D3FB79F003F57D7 /* MGLLineStyleLayer.h */,
 				35136D3E1D42273000C20EFD /* MGLLineStyleLayer.mm */,
 				DA7262091DEEE3480043BB89 /* MGLOpenGLStyleLayer.h */,
@@ -1572,6 +1576,7 @@
 				35E1A4D81D74336F007AA97F /* MGLValueEvaluator.h in Headers */,
 				DA88482C1CBAFA6200AB86E3 /* NSBundle+MGLAdditions.h in Headers */,
 				357FE2DD1E02D2B20068B753 /* NSCoder+MGLAdditions.h in Headers */,
+				522ADA011E955C2F00096484 /* MGLForegroundStyleLayer_Private.h in Headers */,
 				7E016D7E1D9E86BE00A29A21 /* MGLPolyline+MGLAdditions.h in Headers */,
 				35D13AB71D3D15E300AFB4E0 /* MGLStyleLayer.h in Headers */,
 				DA88488E1CBB047F00AB86E3 /* reachability.h in Headers */,
@@ -1712,6 +1717,7 @@
 				353AFA151D65AB17005A69F4 /* NSDate+MGLAdditions.h in Headers */,
 				3510FFFA1D6DCC4700F413B2 /* NSCompoundPredicate+MGLAdditions.h in Headers */,
 				DA72620C1DEEE3480043BB89 /* MGLOpenGLStyleLayer.h in Headers */,
+				522ADA021E955C3000096484 /* MGLForegroundStyleLayer_Private.h in Headers */,
 				35CE61831D4165D9004F2359 /* UIColor+MGLAdditions.h in Headers */,
 				DABFB8671CBE99E500D62B32 /* MGLPolygon.h in Headers */,
 				404C26E81D89C55D000AA13D /* MGLTileSource_Private.h in Headers */,
@@ -2141,7 +2147,7 @@
 				3566C7681D4A77BA008152BC /* MGLShapeSource.mm in Sources */,
 				400533021DB0862B0069F638 /* NSArray+MGLAdditions.mm in Sources */,
 				35136D421D42274500C20EFD /* MGLRasterStyleLayer.mm in Sources */,
-				3538AA1F1D542239008EC33D /* MGLForegroundStyleLayer.m in Sources */,
+				3538AA1F1D542239008EC33D /* MGLForegroundStyleLayer.mm in Sources */,
 				DA00FC901D5EEB0D009AABC8 /* MGLAttributionInfo.mm in Sources */,
 				DA88482D1CBAFA6200AB86E3 /* NSBundle+MGLAdditions.m in Sources */,
 				DA88485B1CBAFB9800AB86E3 /* MGLUserLocation.m in Sources */,
@@ -2219,7 +2225,7 @@
 				3566C7691D4A77BA008152BC /* MGLShapeSource.mm in Sources */,
 				400533031DB086490069F638 /* NSArray+MGLAdditions.mm in Sources */,
 				35136D431D42274500C20EFD /* MGLRasterStyleLayer.mm in Sources */,
-				3538AA201D542239008EC33D /* MGLForegroundStyleLayer.m in Sources */,
+				3538AA201D542239008EC33D /* MGLForegroundStyleLayer.mm in Sources */,
 				DA00FC911D5EEB0D009AABC8 /* MGLAttributionInfo.mm in Sources */,
 				DAA4E4201CBB730400178DFB /* MGLOfflinePack.mm in Sources */,
 				DAA4E4331CBB730400178DFB /* MGLUserLocation.m in Sources */,