Move around GL dependencies.

  :gpu gets GL and GLU
  :gpu_tool_utils gets X11
  :views gets GL and X11

{shared,static}x{gpu,no-gpu} all seem to link.
May not be perfect, but it's a start.

CQ_INCLUDE_TRYBOTS=skia.primary:Build-Ubuntu-GCC-x86_64-Debug-NoGPU,Build-Ubuntu-GCC-x86_64-Release-Shared

Change-Id: Ia6f595a9d601f623a3c686aa00528a80401bcb24
Reviewed-on: https://skia-review.googlesource.com/8911
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index 8aaa913..c162842 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -407,6 +407,10 @@
     sources += [ "src/gpu/gl/android/GrGLCreateNativeInterface_android.cpp" ]
   } else if (is_linux) {
     sources += [ "src/gpu/gl/glx/GrGLCreateNativeInterface_glx.cpp" ]
+    libs += [
+      "GL",
+      "GLU",
+    ]
   } else if (is_mac) {
     sources += [ "src/gpu/gl/mac/GrGLCreateNativeInterface_mac.cpp" ]
   } else if (is_ios) {
@@ -674,11 +678,6 @@
   }
 
   if (is_linux) {
-    libs += [
-      "GL",
-      "GLU",
-      "X11",
-    ]
     sources += [ "src/ports/SkDebug_stdio.cpp" ]
   }
 
@@ -857,6 +856,7 @@
         libs += [ "OpenGLES.framework" ]
       } else if (is_linux) {
         sources += [ "tools/gpu/gl/glx/CreatePlatformGLTestContext_glx.cpp" ]
+        libs += [ "X11" ]
       } else if (is_mac) {
         sources += [ "tools/gpu/gl/mac/CreatePlatformGLTestContext_mac.cpp" ]
       } else if (is_win) {
@@ -1033,6 +1033,10 @@
         "src/views/unix/SkOSWindow_Unix.cpp",
         "src/views/unix/keysym2ucs.c",
       ]
+      libs += [
+        "GL",
+        "X11",
+      ]
     } else if (is_mac) {
       sources += [
         "src/views/mac/SkEventNotifier.mm",