Add a test case for gradients with opacity.

BUG=chromium:668762

Change-Id: I99de143c6c981336994c17d8470dd9c1862bdfa3
Reviewed-on: https://pdfium-review.googlesource.com/39290
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>

pdfium/bug_668762.pdf

diff --git a/pdfium/bug_668762.pdf b/pdfium/bug_668762.pdf
new file mode 100644
index 0000000..49340de
--- /dev/null
+++ b/pdfium/bug_668762.pdf
@@ -0,0 +1,121 @@
+%PDF-1.3
+%ÿÿÿÿ
+6 0 obj
+<<
+/FunctionType 2
+/Domain [0 1]
+/C0 [0 0.5019607843137255 0]
+/C1 [0.9333333333333333 0.5098039215686274 0.9333333333333333]
+/N 1
+>>
+endobj
+7 0 obj
+<<
+/ShadingType 3
+/ColorSpace /DeviceRGB
+/Coords [300 300 0 300 300 300]
+/Function 6 0 R
+/Extend [true true]
+>>
+endobj
+8 0 obj
+<<
+/Type /Pattern
+/PatternType 2
+/Shading 7 0 R
+/Matrix [1 0 0 -1 0 600]
+>>
+endobj
+10 0 obj
+<<
+/Type /ExtGState
+/ca 0.1
+>>
+endobj
+5 0 obj
+<<
+/Type /Page
+/Parent 1 0 R
+/MediaBox [0 0 600 600]
+/Contents 3 0 R
+/Resources 4 0 R
+>>
+endobj
+4 0 obj
+<<
+/ProcSet [/PDF /Text /ImageB /ImageC /ImageI]
+/Pattern <<
+/Sh1 8 0 R
+>>
+/Font <<
+/F1 9 0 R
+>>
+/ExtGState <<
+/Gs1 10 0 R
+>>
+>>
+endobj
+3 0 obj
+<<
+/Length 95
+>>
+stream
+1 0 0 -1 0 600 cm
+/Pattern cs
+/Sh1 scn
+/Gs1 gs
+BT /F1 800 Tf 0 Tr 1 0 0 -1 35 585 Tm (A) Tj ET
+
+endstream
+endobj
+11 0 obj
+<<
+/Producer (PDFKit)
+/Creator (PDFKit)
+/CreationDate (D:20161126005727Z)
+>>
+endobj
+9 0 obj
+<<
+/Type /Font
+/BaseFont /Helvetica
+/Subtype /Type1
+/Encoding /WinAnsiEncoding
+>>
+endobj
+2 0 obj
+<<
+/Type /Catalog
+/Pages 1 0 R
+>>
+endobj
+1 0 obj
+<<
+/Type /Pages
+/Count 1
+/Kids [5 0 R]
+>>
+endobj
+xref
+0 12
+0000000000 65535 f 
+0000001060 00000 n 
+0000001011 00000 n 
+0000000676 00000 n 
+0000000532 00000 n 
+0000000428 00000 n 
+0000000015 00000 n 
+0000000163 00000 n 
+0000000290 00000 n 
+0000000914 00000 n 
+0000000381 00000 n 
+0000000821 00000 n 
+trailer
+<<
+/Size 12
+/Root 2 0 R
+/Info 11 0 R
+>>
+startxref
+1117
+%%EOF

pdfium/bug_668762_expected.pdf.0.png

diff --git a/pdfium/bug_668762_expected.pdf.0.png b/pdfium/bug_668762_expected.pdf.0.png
new file mode 100644
index 0000000..5cab8dd
--- /dev/null
+++ b/pdfium/bug_668762_expected.pdf.0.png
Binary files differ