Roll pdfium.

This brings in:
02e6ca4  Fix compile on mac: format string mismatch error.
1b04ea3  Set m_pLinearized to NULL after release
a3c7215  Perform better input checks in early steps of parser.
1dfbe60  Use number of components from ICC profile and alternate color space
187483a  Add GetValidBpc() check in CPDF_DIBSource::CreateDecoder()
c2442f9  Add GetValidBpc() check in CPDF_DIBSource::GetScanLine
a550e4c  Revert of Use number of components from ICC profile and alternateCS (patchset #1 of
c655167  Fix the issue 'SEGV on unknown address in CPDF_DataAvail::GetObjectSize'
aeacba4  Fix a hang issue due to inconsistent page number in the test file
02132dc  Bounds check in CFX_Font::LoadGlyphPath().
48f26c5  Fix confusion between length in bytes and length in characters in app::response().
e9bf0e9  Don't stretch bitmaps if destination size is empty.
ee6088e  Check the number of component in ICCBased colorspace
4fb24f3  For pattern colorspace, its base colorspace should not be a pattern colorspace
8f2c3dc  Check if user provided more than one option for pdfium_test.
93d0811  Fix bug in CPDF_PageContentGenerate constructor and destructor
8cf33bc  Fixed command line parting when no output is needed.
2d55db1  Font is used after release in CPDF_TextStateData::~CPDF_TextStateData
39a97ea  Fix a double-free issue in CFX_PathData::~CFX_PathData
a94019d  Check path point count overflow in DrawThisAppearance
91177a4  Add a null check before getting unicode text in CPDF_FormField::GetValue
4f38edb  Add a null pointer check before getting the family name of the given color space in

TBR=thakis@chromium.org
TBR=inferno@chromium.org

Review URL: https://codereview.chromium.org/494063003

Cr-Commit-Position: refs/heads/master@{#292006}

DEPS

@@ -66,7 +66,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFIum
   # and whatever else without interference from each other.
-  'pdfium_revision': '635e82ec20b3d5ffcb24f9a1b1be9f1f24d8a3f4',
+  'pdfium_revision': '02e6ca4c4fc94f72fa7aac326234dfd8a9f61d23',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling openmax_dl
   # and whatever else without interference from each other.