Roll pdfium, add GN build for pdf and pdfium.

Pdfium changes:
d68f9a3  Add GN build file for pdfium, rename GYP target.
f0a5576  fix two uninitialized reads
https://code.google.com/p/pdfium/issues/detail?id=9
https://code.google.com/p/pdfium/issues/detail?id=10
bb2b1e7  Use unsigned type for iteration to avoid int overflow.
62a7fd6  Wrong variable assignment in Pdfium.

In the GN build this separates out the no-exceptions flag since pdfium must be compiled with exceptions enabled.

Updates pdfium naming in GYP from fpdfsdk.

Removes src/pdf from .gitignore now that it is checked in.

BUG=
R=jam@chromium.org

Review URL: https://codereview.chromium.org/315313002

git-svn-id: http://src.chromium.org/svn/trunk/src/build@275269 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

config/BUILDCONFIG.gn

@@ -329,7 +329,15 @@ if (is_win) {
     "//build/config/win:sdk",
     "//build/config/win:unicode",
   ]
-} else if (is_linux) {
+}
+if (is_posix) {
+  _native_compiler_configs += [
+    "//build/config/gcc:no_exceptions",
+    "//build/config/gcc:symbol_visibility_hidden",
+  ]
+}
+
+if (is_linux) {
   _native_compiler_configs += [ "//build/config/linux:sdk", ]
 } else if (is_mac) {
   _native_compiler_configs += [ "//build/config/mac:sdk", ]
@@ -338,9 +346,7 @@ if (is_win) {
 } else if (is_android) {
   _native_compiler_configs += [ "//build/config/android:sdk", ]
 }
-if (!is_win) {
-  _native_compiler_configs += [ "//build/config/gcc:symbol_visibility_hidden" ]
-}
+
 if (is_clang) {
   _native_compiler_configs += [
     "//build/config/clang:find_bad_constructs",

config/compiler/BUILD.gn

@@ -58,7 +58,6 @@ config("compiler") {
       "-fno-strict-aliasing",  # See http://crbug.com/32204
     ]
     cflags_cc += [
-      "-fno-exceptions",
       "-fno-threadsafe-statics",
       # Not exporting C++ inline functions can generally be applied anywhere
       # so we do so here. Normal function visibility is controlled by

config/gcc/BUILD.gn

@@ -35,3 +35,7 @@ config("executable_ldconfig") {
     ]
   }
 }
+
+config("no_exceptions") {
+  cflags_cc = [ "-fno-exceptions" ]
+}