Merge to XFA: Add path service to retrieve test data directory at run time so tests can be run from any directory.

Previously the tests which read test files assume the current directory is under pdfium. Running from any other directory will break the build.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1408003014 .

(cherry picked from commit c0e93a9a942fe7d99800502a61d2fbb58cf9276f)

Conflicts:
	core/src/fpdfapi/fpdf_parser/fpdf_parser_parser_embeddertest.cpp
	fpdfsdk/src/fpdfdoc_embeddertest.cpp
	testing/embedder_test.cpp
	testing/embedder_test.h

Review URL: https://codereview.chromium.org/1411403012 .
diff --git a/fpdfsdk/src/fpdftext_embeddertest.cpp b/fpdfsdk/src/fpdftext_embeddertest.cpp
index 52cec70..6c1ae4c 100644
--- a/fpdfsdk/src/fpdftext_embeddertest.cpp
+++ b/fpdfsdk/src/fpdftext_embeddertest.cpp
@@ -2,9 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "../../testing/embedder_test.h"
 #include "public/fpdf_text.h"
 #include "public/fpdfview.h"
+#include "testing/embedder_test.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
@@ -28,7 +28,7 @@
 class FPDFTextEmbeddertest : public EmbedderTest {};
 
 TEST_F(FPDFTextEmbeddertest, Text) {
-  EXPECT_TRUE(OpenDocument("testing/resources/hello_world.pdf"));
+  EXPECT_TRUE(OpenDocument("hello_world.pdf"));
   FPDF_PAGE page = LoadPage(0);
   EXPECT_NE(nullptr, page);
 
@@ -136,7 +136,7 @@
 }
 
 TEST_F(FPDFTextEmbeddertest, TextSearch) {
-  EXPECT_TRUE(OpenDocument("testing/resources/hello_world.pdf"));
+  EXPECT_TRUE(OpenDocument("hello_world.pdf"));
   FPDF_PAGE page = LoadPage(0);
   EXPECT_NE(nullptr, page);
 
@@ -243,7 +243,7 @@
 
 // Test that the page has characters despite a bad stream length.
 TEST_F(FPDFTextEmbeddertest, StreamLengthPastEndOfFile) {
-  EXPECT_TRUE(OpenDocument("testing/resources/bug_57.pdf"));
+  EXPECT_TRUE(OpenDocument("bug_57.pdf"));
   FPDF_PAGE page = LoadPage(0);
   EXPECT_NE(nullptr, page);
 
@@ -256,7 +256,7 @@
 }
 
 TEST_F(FPDFTextEmbeddertest, WebLinks) {
-  EXPECT_TRUE(OpenDocument("testing/resources/weblinks.pdf"));
+  EXPECT_TRUE(OpenDocument("weblinks.pdf"));
   FPDF_PAGE page = LoadPage(0);
   EXPECT_NE(nullptr, page);