Forward handling of low-mem message to the content renderer client. Add APIs to handle this case.

chrome/renderer/chrome_render_process_observer.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/chrome_render_process_observer.h"
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/native_library.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/threading/platform_thread.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension_localization_peer.h"
 #include "chrome/common/net/net_resource_provider.h"
 #include "chrome/common/render_messages.h"
+#include "chrome/renderer/chrome_content_renderer_client.h"
 #include "chrome/renderer/content_settings_observer.h"
 #include "chrome/renderer/security_filter_peer.h"
 #include "content/common/resource_dispatcher.h"
 #include "content/common/resource_dispatcher_delegate.h"
 #include "content/common/view_messages.h"
 #include "content/renderer/render_thread.h"
 #include "content/renderer/render_view.h"
 #include "content/renderer/render_view_visitor.h"
 #include "crypto/nss_util.h"
 #include "media/base/media.h"
@@ skipping 268 matching lines @@
   const int shutdown_fd_;
 
   DISALLOW_COPY_AND_ASSIGN(ShutdownDetector);
 };
 #endif  // OS_MACOSX
 
 }  // namespace
 
 bool ChromeRenderProcessObserver::is_incognito_process_ = false;
 
-ChromeRenderProcessObserver::ChromeRenderProcessObserver() {
+ChromeRenderProcessObserver::ChromeRenderProcessObserver(
+    chrome::ChromeContentRendererClient* client)
+    : client_(client) {
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
   if (command_line.HasSwitch(switches::kEnableWatchdog)) {
     // TODO(JAR): Need to implement renderer IO msgloop watchdog.
   }
 
   if (command_line.HasSwitch(switches::kDumpHistogramsOnExit)) {
     base::StatisticsRecorder::set_dump_on_exit(true);
   }
 
   RenderThread* thread = RenderThread::current();
@@ skipping 156 matching lines @@
 }
 
 void ChromeRenderProcessObserver::OnGetV8HeapStats() {
   v8::HeapStatistics heap_stats;
   v8::V8::GetHeapStatistics(&heap_stats);
   Send(new ViewHostMsg_V8HeapStats(heap_stats.total_heap_size(),
                                    heap_stats.used_heap_size()));
 }
 
 void ChromeRenderProcessObserver::OnPurgeMemory() {
+  LOG(INFO) << "CRPO purging memory!";

[jam, 2011/07/22 16:31:50]

ditto

[Greg Billock, 2011/07/22 17:02:07]

removed

On 2011/07/22 16:31:50, John Abd-El-Malek wrote:

   // Clear the object cache (as much as possible; some live objects cannot be
   // freed).
   WebCache::clear();
 
   // Clear the font/glyph cache.
   WebFontCache::clear();
 
   // Clear the Cross-Origin Preflight cache.
   WebCrossOriginPreflightResultCache::clear();
 
   // Release all freeable memory from the SQLite process-global page cache (a
   // low-level object which backs the Connection-specific page caches).
   while (sqlite3_release_memory(std::numeric_limits<int>::max()) > 0) {
   }
 
   // Repeatedly call the V8 idle notification until it returns true ("nothing
   // more to free").  Note that it makes more sense to do this than to implement
   // a new "delete everything" pass because object references make it difficult
   // to free everything possible in just one pass.
   while (!v8::V8::IdleNotification()) {
   }
 
 #if !defined(OS_MACOSX) && defined(USE_TCMALLOC)
   // Tell tcmalloc to release any free pages it's still holding.
   MallocExtension::instance()->ReleaseFreeMemory();
 #endif
+
+  if (client_)

[jam, 2011/07/22 16:31:50]

nit: can client_ ever be NULL? if not then no need for this

[Greg Billock, 2011/07/22 17:02:07]

For unit tests and such it can, so I thought this would be best.

+    client_->OnPurgeMemory();
 }