Consolidate bounding box logic.

Move all the checks into the shared helper functions for getting/setting
bounding boxes.

Change-Id: I6f597f478fd3510e0528d20a0a7820949600fd2a
Reviewed-on: https://pdfium-review.googlesource.com/34692
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

fpdfsdk/fpdf_transformpage.cpp

diff --git a/fpdfsdk/fpdf_transformpage.cpp b/fpdfsdk/fpdf_transformpage.cpp
index af6ac79..267b582 100644
--- a/fpdfsdk/fpdf_transformpage.cpp
+++ b/fpdfsdk/fpdf_transformpage.cpp
@@ -28,7 +28,8 @@
 void SetBoundingBox(CPDF_Page* page,
                     const ByteString& key,
                     const CFX_FloatRect& rect) {
-  page->GetDict()->SetRectFor(key, rect);
+  if (page)
+    page->GetDict()->SetRectFor(key, rect);
 }
 
 bool GetBoundingBox(CPDF_Page* page,
@@ -37,7 +38,7 @@
                     float* bottom,
                     float* right,
                     float* top) {
-  if (!left || !bottom || !right || !top)
+  if (!page || !left || !bottom || !right || !top)
     return false;
 
   CPDF_Array* pArray = page->GetDict()->GetArrayFor(key);
@@ -64,11 +65,7 @@
                                                     float bottom,
                                                     float right,
                                                     float top) {
-  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
-  if (!pPage)
-    return;
-
-  SetBoundingBox(pPage, pdfium::page_object::kMediaBox,
+  SetBoundingBox(CPDFPageFromFPDFPage(page), pdfium::page_object::kMediaBox,
                  CFX_FloatRect(left, bottom, right, top));
 }
 
@@ -77,11 +74,7 @@
                                                    float bottom,
                                                    float right,
                                                    float top) {
-  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
-  if (!pPage)
-    return;
-
-  SetBoundingBox(pPage, pdfium::page_object::kCropBox,
+  SetBoundingBox(CPDFPageFromFPDFPage(page), pdfium::page_object::kCropBox,
                  CFX_FloatRect(left, bottom, right, top));
 }
 
@@ -90,9 +83,9 @@
                                                          float* bottom,
                                                          float* right,
                                                          float* top) {
-  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
-  return pPage && GetBoundingBox(pPage, pdfium::page_object::kMediaBox, left,
-                                 bottom, right, top);
+  return GetBoundingBox(CPDFPageFromFPDFPage(page),
+                        pdfium::page_object::kMediaBox, left, bottom, right,
+                        top);
 }
 
 FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPage_GetCropBox(FPDF_PAGE page,
@@ -100,9 +93,9 @@
                                                         float* bottom,
                                                         float* right,
                                                         float* top) {
-  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
-  return pPage && GetBoundingBox(pPage, pdfium::page_object::kCropBox, left,
-                                 bottom, right, top);
+  return GetBoundingBox(CPDFPageFromFPDFPage(page),
+                        pdfium::page_object::kCropBox, left, bottom, right,
+                        top);
 }
 
 FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV