Don't dereference NULL pointers.

According to render_widget_host.h, view() can return NULL. This patch checks
the value of view() before dereferencing it.

BUG=crash reports indicate failure at point of dereferencing
TEST=none (don't know how to repro)

Review URL: http://codereview.chromium.org/6250084

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@73452 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 28 insertions, 19 deletions

diff --git a/chrome/browser/gpu_process_host.cc b/chrome/browser/gpu_process_host.cc
index a1e8a66..5782c0b 100644
--- a/chrome/browser/gpu_process_host.cc
+++ b/chrome/browser/gpu_process_host.cc
@@ -264,25 +264,31 @@ void CVCBThreadHopping::GetViewWindow(
     host = static_cast<RenderWidgetHost*>(
         process->GetListenerByID(render_view_id));
   }
-#if defined(OS_LINUX)
-  gfx::NativeViewId view = NULL;
+
+  RenderWidgetHostView* view = NULL;
   if (host)
-    view = gfx::IdFromNativeView(host->view()->GetNativeView());
+    view = host->view();
 
-  // Lock the window that we will draw into.
-  GtkNativeViewManager* manager = GtkNativeViewManager::GetInstance();
-  if (!manager->GetPermanentXIDForId(&window, view)) {
-    DLOG(ERROR) << "Can't find XID for view id " << view;
-  }
+  if (view) {
+#if defined(OS_LINUX)
+    gfx::NativeViewId view_id = NULL;
+    view_id = gfx::IdFromNativeView(view->GetNativeView());
+
+    // Lock the window that we will draw into.
+    GtkNativeViewManager* manager = GtkNativeViewManager::GetInstance();
+    if (!manager->GetPermanentXIDForId(&window, view_id)) {
+      DLOG(ERROR) << "Can't find XID for view id " << view_id;
+    }
 #elif defined(OS_MACOSX)
-  // On Mac OS X we currently pass a (fake) PluginWindowHandle for the
-  // window that we draw to.
-  window = host->view()->AllocateFakePluginWindowHandle(
-      /*opaque=*/true, /*root=*/true);
+    // On Mac OS X we currently pass a (fake) PluginWindowHandle for the
+    // window that we draw to.
+    window = view->AllocateFakePluginWindowHandle(
+        /*opaque=*/true, /*root=*/true);
 #elif defined(OS_WIN)
-  // Create a window that we will overlay.
-  window = host->view()->GetCompositorHostWindow();
+    // Create a window that we will overlay.
+    window = view->GetCompositorHostWindow();
 #endif
+  }
 
   BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, NewRunnableFunction(
       &CVCBThreadHopping::DispatchIPCAndQueueReply,
diff --git a/chrome/browser/gpu_process_host_ui_shim.cc b/chrome/browser/gpu_process_host_ui_shim.cc
index ebf7e06..43b5df1 100644
--- a/chrome/browser/gpu_process_host_ui_shim.cc
+++ b/chrome/browser/gpu_process_host_ui_shim.cc
@@ -129,14 +129,17 @@ void GpuProcessHostUIShim::OnDestroyCommandBuffer(
     host = static_cast<RenderWidgetHost*>(
         process->GetListenerByID(render_view_id));
   }
-  if (!host)
-    return;
+  RenderWidgetHostView* view = NULL;
+  if (host)
+    view = host->view();
+
+  if (view) {
 #if defined(OS_MACOSX)
-  host->view()->DestroyFakePluginWindowHandle(window);
+    view->DestroyFakePluginWindowHandle(window);
 #elif defined(OS_WIN)
-  host->view()->ShowCompositorHostWindow(false);
+    view->ShowCompositorHostWindow(false);
 #endif
-
+  }
 #endif  // defined(OS_MACOSX) || defined(OS_WIN)
 }