Rename webkit_shared to webkit and use source sets

web_view is depending on the webkit rather than webkit_shared target.
The use of source sets is needed to avoid hitting the 4GB static
archive limit (llvm-ar doesn't support 64-bit archives).

Change-Id: Ib406e403da4079e93a624125a6660284e21d241e
diff --git a/BUILD.gn b/BUILD.gn
index d0f2370..b1ecc06 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -39,9 +39,7 @@
   include_dirs = [ "Source/WebKit/fuchsia" ]
 }
 
-shared_library("webkit_shared") {
-  output_name = "libwebkit"
-
+shared_library("webkit") {
   deps = [
     ":WebKit",
   ]
@@ -266,7 +264,7 @@
   defines = []
 }
 
-static_library("WebCore") {
+source_set("WebCore") {
   sources = WebCore_sources + WebCoreDerivedSources_sources
 
   public_deps = [
@@ -339,7 +337,7 @@
   }
 }
 
-static_library("JavaScriptCore") {
+source_set("JavaScriptCore") {
   sources = JavaScriptCore_sources + JavaScriptCoreDerivedSources_sources +
             JavaScriptCore_inspectorDerivedSources_sources
 
@@ -389,7 +387,7 @@
   ]
 }
 
-static_library("wtf") {
+source_set("wtf") {
   sources = wtf_sources
 
   public_configs = [ ":wtf_config" ]