Consolidate Windows bitmap and DC code

skia/ext/skia_utils_win.cc

Index: skia/ext/skia_utils_win.cc
diff --git a/skia/ext/skia_utils_win.cc b/skia/ext/skia_utils_win.cc
index 37bd21e3c898ac1cd0432d89f0c6d999983773c9..b0aff357adbbcfb1ae01bafc415d0bf987e15948 100644
--- a/skia/ext/skia_utils_win.cc
+++ b/skia/ext/skia_utils_win.cc
@@ -7,9 +7,9 @@
 #include <stddef.h>
 #include <windows.h>
 
+#include "base/debug/gdi_debug_util_win.h"
 #include "third_party/skia/include/core/SkRect.h"
 #include "third_party/skia/include/core/SkTypes.h"
-#include "third_party/skia/include/effects/SkGradientShader.h"
 
 namespace {
 
@@ -148,5 +148,40 @@ void CopyHDC(HDC source, HDC destination, int x, int y, bool is_opaque,
   LoadTransformToDC(source, transform);
 }
 
+HBITMAP CreateHBitmap(int width, int height, bool is_opaque,
+                      HANDLE shared_section, void** data) {
+  // CreateDIBSection appears to get unhappy if we create an empty bitmap, so
+  // just create a minimal bitmap
+  if ((width == 0) || (height == 0)) {
+    width = 1;
+    height = 1;
+  }
+
+  BITMAPINFOHEADER hdr = {0};
+  hdr.biSize = sizeof(BITMAPINFOHEADER);
+  hdr.biWidth = width;
+  hdr.biHeight = -height;  // minus means top-down bitmap
+  hdr.biPlanes = 1;
+  hdr.biBitCount = 32;
+  hdr.biCompression = BI_RGB;  // no compression
+  hdr.biSizeImage = 0;
+  hdr.biXPelsPerMeter = 1;
+  hdr.biYPelsPerMeter = 1;
+  hdr.biClrUsed = 0;
+  hdr.biClrImportant = 0;
+
+  HBITMAP hbitmap = CreateDIBSection(NULL, reinterpret_cast<BITMAPINFO*>(&hdr),
+                                     0, data, shared_section, 0);
+
+#if !defined(_WIN64)
+  // If this call fails, we're gonna crash hard. Try to get some useful
+  // information out before we crash for post-mortem analysis.
+  if (!hbitmap)
+    base::debug::GDIBitmapAllocFailure(&hdr, shared_section);
+#endif
+
+  return hbitmap;
+}
+
 }  // namespace skia