Compile ui/gfx on Fuchsia

1. Added stubs for typedefs in native_widget_types.h
2. Updated skia/ext/platform_canvas.h to define
   CreatePlatformCanvasWithPixels on Fuchsia

Bug: 731302
Change-Id: Ibfcb3d522ff87d24c17677be8f09e7f3b3a9d9a6
Reviewed-on: https://chromium-review.googlesource.com/557219
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#483569}

skia/ext/platform_canvas.h

@@ -57,9 +57,10 @@ SK_API std::unique_ptr<SkCanvas> CreatePlatformCanvasWithSharedSection(
 SK_API HDC GetNativeDrawingContext(SkCanvas* canvas);
 
 #elif defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__) || \
-      defined(__sun) || defined(ANDROID) || defined(__APPLE__)
-  // Construct a canvas from the given memory region. The memory is not cleared
-  // first. @data must be, at least, @height * StrideForWidth(@width) bytes.
+    defined(__sun) || defined(ANDROID) || defined(__APPLE__) ||             \
+    defined(__Fuchsia__)
+// Construct a canvas from the given memory region. The memory is not cleared
+// first. @data must be, at least, @height * StrideForWidth(@width) bytes.
 SK_API std::unique_ptr<SkCanvas> CreatePlatformCanvasWithPixels(
     int width,
     int height,

ui/gfx/native_widget_types.h

@@ -133,6 +133,12 @@ typedef void* NativeCursor;
 typedef ui::ViewAndroid* NativeView;
 typedef ui::WindowAndroid* NativeWindow;
 typedef jobject NativeEvent;
+#elif defined(OS_FUCHSIA)
+// TODO(fuchsia): Update when we have a plan for UI on Fuchsia.
+typedef void* NativeCursor;
+typedef void* NativeView;
+typedef void* NativeWindow;
+typedef void* NativeEvent;
 #else
 #error Unknown build environment.
 #endif
@@ -197,6 +203,10 @@ constexpr AcceleratedWidget kNullAcceleratedWidget = 0;
 #elif defined(USE_OZONE)
 typedef int32_t AcceleratedWidget;
 constexpr AcceleratedWidget kNullAcceleratedWidget = 0;
+#elif defined(OS_FUCHSIA)
+// TODO(fuchsia): Update when we have a plan for UI on Fuchsia.
+typedef void* AcceleratedWidget;
+constexpr AcceleratedWidget kNullAcceleratedWidget = 0;
 #else
 #error unknown platform
 #endif