From a6df44456956914e86b9d9af722b30628c45f208 Mon Sep 17 00:00:00 2001
From: art-snake <art-snake@yandex-team.ru>
Date: Tue, 20 Sep 2016 11:59:02 -0700
Subject: Fix memory leaking on ClosePage.

BUG=79367, 48791

The fonts was not cleared after unloading pages.

Test pdf: http://www.nasa.gov/pdf/750614main_NASA_FY_2014_Budget_Estimates-508.pdf
 For this file, we have ~5 fonts per page, which equal ~1 Mb per page.
 In this PDF we have 670 pages, as result after slow scrolling(reading) full document we have ~600 Mb fonts data in memory.

Memory usage of PDF Plugin:
 before this CL: ~660 Mb
 after this CL: ~100 Mb

This is last part of reverted CL:
 Original CL: https://codereview.chromium.org/2158023002
 Revert reason: BUG=647612
 Fix bug CL: https://codereview.chromium.org/2350193003
 Previous CL: https://codereview.chromium.org/2350243002

Review-Url: https://codereview.chromium.org/2351193002
---
 core/fpdfapi/fpdf_page/fpdf_page_doc.cpp | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/core/fpdfapi/fpdf_page/fpdf_page_doc.cpp b/core/fpdfapi/fpdf_page/fpdf_page_doc.cpp
index 9e586e326f..e050060a9e 100644
--- a/core/fpdfapi/fpdf_page/fpdf_page_doc.cpp
+++ b/core/fpdfapi/fpdf_page/fpdf_page_doc.cpp
@@ -214,9 +214,10 @@ void CPDF_DocPageData::ReleaseFont(const CPDF_Dictionary* pFontDict) {
     return;
 
   pFontData->RemoveRef();
-  if (pFontData->use_count() != 0)
+  if (pFontData->use_count() > 1)
     return;
 
+  // We have font data only in m_FontMap cache. Clean it.
   pFontData->clear();
 }
 
@@ -330,9 +331,10 @@ void CPDF_DocPageData::ReleaseColorSpace(const CPDF_Object* pColorSpace) {
     return;
 
   pCountedColorSpace->RemoveRef();
-  if (pCountedColorSpace->use_count() != 0)
+  if (pCountedColorSpace->use_count() > 1)
     return;
 
+  // We have item only in m_ColorSpaceMap cache. Clean it.
   pCountedColorSpace->get()->ReleaseCS();
   pCountedColorSpace->reset(nullptr);
 }
@@ -391,9 +393,10 @@ void CPDF_DocPageData::ReleasePattern(const CPDF_Object* pPatternObj) {
     return;
 
   pPattern->RemoveRef();
-  if (pPattern->use_count() != 0)
+  if (pPattern->use_count() > 1)
     return;
 
+  // We have item only in m_PatternMap cache. Clean it.
   pPattern->clear();
 }
 
@@ -429,9 +432,10 @@ void CPDF_DocPageData::ReleaseImage(const CPDF_Object* pImageStream) {
     return;
 
   pCountedImage->RemoveRef();
-  if (pCountedImage->use_count() != 0)
+  if (pCountedImage->use_count() > 1)
     return;
 
+  // We have item only in m_ImageMap cache. Clean it.
   delete pCountedImage->get();
   delete pCountedImage;
   m_ImageMap.erase(it);
@@ -454,7 +458,8 @@ CPDF_IccProfile* CPDF_DocPageData::GetIccProfile(
   auto hash_it = m_HashProfileMap.find(bsDigest);
   if (hash_it != m_HashProfileMap.end()) {
     auto it_copied_stream = m_IccProfileMap.find(hash_it->second);
-    return it_copied_stream->second->AddRef();
+    if (it_copied_stream != m_IccProfileMap.end())
+      return it_copied_stream->second->AddRef();
   }
   CPDF_IccProfile* pProfile =
       new CPDF_IccProfile(stream.GetData(), stream.GetSize());
@@ -473,12 +478,13 @@ void CPDF_DocPageData::ReleaseIccProfile(const CPDF_IccProfile* pIccProfile) {
       continue;
 
     profile->RemoveRef();
-    if (profile->use_count() == 0) {
-      delete profile->get();
-      delete profile;
-      m_IccProfileMap.erase(it);
-      return;
-    }
+    if (profile->use_count() > 1)
+      continue;
+    // We have item only in m_IccProfileMap cache. Clean it.
+    delete profile->get();
+    delete profile;
+    m_IccProfileMap.erase(it);
+    return;
   }
 }
 
@@ -518,9 +524,10 @@ void CPDF_DocPageData::ReleaseFontFileStreamAcc(
     return;
 
   pCountedStream->RemoveRef();
-  if (pCountedStream->use_count() != 0)
+  if (pCountedStream->use_count() > 1)
     return;
 
+  // We have item only in m_FontFileMap cache. Clean it.
   delete pCountedStream->get();
   delete pCountedStream;
   m_FontFileMap.erase(it);
-- 
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