cc: Remove all usage of GetArea() from production code in cc

Consolidate the calls to turn gfx::Size into a number of bytes onto
the cc::SharedBitmap class. The class offers the following methods:
1. Get a size_t bytes and bool saying if you overflowed or not.
2. Get a size_t bytes and crash if you overflow.
3. Get a size_t bytes and don't check for overflow.
4. Tell me if the gfx::Size would overflow to create the size_t bytes.

These were the use cases I found in the existing code, plus the
addition of case 2. A few places that were finding the size_t bytes
without looking for overflow (case 3), from a previously-unchecked
gfx::Size, were changed to crash on overflow instead (case 2).

R=jbauman@chromium.org, piman@chromium.org
BUG=348332

Review URL: https://codereview.chromium.org/221523003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@261817 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 15 insertions, 11 deletions

diff --git a/content/browser/renderer_host/software_frame_manager.cc b/content/browser/renderer_host/software_frame_manager.cc
index 3630e59..d4fc273 100644
--- a/content/browser/renderer_host/software_frame_manager.cc
+++ b/content/browser/renderer_host/software_frame_manager.cc
@@ -8,6 +8,7 @@
 #include "base/callback_helpers.h"
 #include "base/debug/alias.h"
 #include "base/numerics/safe_math.h"
+#include "cc/resources/shared_bitmap.h"
 #include "content/browser/renderer_host/dip_util.h"
 #include "content/public/browser/user_metrics.h"
 
@@ -97,9 +98,11 @@ bool SoftwareFrameManager::SwapToNewFrame(
 
   // The NULL handle is used in testing.
   if (base::SharedMemory::IsHandleValid(shared_memory->handle())) {
-    DCHECK(frame_data->CheckedSizeInBytes().IsValid())
-        << "Integer overflow when computing bytes to map.";
-    size_t size_in_bytes = frame_data->SizeInBytes();
+    DCHECK(cc::SharedBitmap::VerifySizeInBytes(frame_data->size));
+    // UncheckedSizeInBytes is okay because the frame_data size was verified
+    // when frame_data was received over IPC.
+    size_t size_in_bytes =
+        cc::SharedBitmap::UncheckedSizeInBytes(frame_data->size);
 #ifdef OS_WIN
     if (!shared_memory->Map(0)) {
       DLOG(ERROR) << "Unable to map renderer memory.";
diff --git a/content/child/child_shared_bitmap_manager.cc b/content/child/child_shared_bitmap_manager.cc
index 7325789..3b1800d 100644
--- a/content/child/child_shared_bitmap_manager.cc
+++ b/content/child/child_shared_bitmap_manager.cc
@@ -25,7 +25,7 @@ scoped_ptr<cc::SharedBitmap> ChildSharedBitmapManager::AllocateSharedBitmap(
                "height",
                size.height());
   size_t memory_size;
-  if (!cc::SharedBitmap::GetSizeInBytes(size, &memory_size))
+  if (!cc::SharedBitmap::SizeInBytes(size, &memory_size))
     return scoped_ptr<cc::SharedBitmap>();
   cc::SharedBitmapId id = cc::SharedBitmap::GenerateId();
   scoped_ptr<base::SharedMemory> memory;
diff --git a/content/common/cc_messages.cc b/content/common/cc_messages.cc
index 40e2441..5279d4c 100644
--- a/content/common/cc_messages.cc
+++ b/content/common/cc_messages.cc
@@ -755,7 +755,7 @@ void ParamTraits<cc::DelegatedFrameData>::Log(const param_type& p,
 
 void ParamTraits<cc::SoftwareFrameData>::Write(Message* m,
                                                const param_type& p) {
-  DCHECK(p.CheckedSizeInBytes().IsValid());
+  DCHECK(cc::SharedBitmap::VerifySizeInBytes(p.size));
 
   m->Reserve(sizeof(cc::SoftwareFrameData));
   WriteParam(m, p.id);
@@ -769,7 +769,8 @@ bool ParamTraits<cc::SoftwareFrameData>::Read(const Message* m,
                                               param_type* p) {
   if (!ReadParam(m, iter, &p->id))
     return false;
-  if (!ReadParam(m, iter, &p->size) || !p->CheckedSizeInBytes().IsValid())
+  if (!ReadParam(m, iter, &p->size) ||
+      !cc::SharedBitmap::VerifySizeInBytes(p->size))
     return false;
   if (!ReadParam(m, iter, &p->damage_rect))
     return false;
diff --git a/content/common/host_shared_bitmap_manager.cc b/content/common/host_shared_bitmap_manager.cc
index aa0cd81..88d9f65 100644
--- a/content/common/host_shared_bitmap_manager.cc
+++ b/content/common/host_shared_bitmap_manager.cc
@@ -62,7 +62,7 @@ scoped_ptr<cc::SharedBitmap> HostSharedBitmapManager::GetSharedBitmapFromId(
   BitmapData* data = it->second.get();
 
   size_t bitmap_size;
-  if (!cc::SharedBitmap::GetSizeInBytes(size, &bitmap_size) ||
+  if (!cc::SharedBitmap::SizeInBytes(size, &bitmap_size) ||
       bitmap_size > data->buffer_size)
     return scoped_ptr<cc::SharedBitmap>();
 
diff --git a/content/common/host_shared_bitmap_manager_unittest.cc b/content/common/host_shared_bitmap_manager_unittest.cc
index 1f7d8dd..ed0ddba 100644
--- a/content/common/host_shared_bitmap_manager_unittest.cc
+++ b/content/common/host_shared_bitmap_manager_unittest.cc
@@ -17,7 +17,7 @@ class HostSharedBitmapManagerTest : public testing::Test {
 TEST_F(HostSharedBitmapManagerTest, TestCreate) {
   gfx::Size bitmap_size(1, 1);
   size_t size_in_bytes;
-  EXPECT_TRUE(cc::SharedBitmap::GetSizeInBytes(bitmap_size, &size_in_bytes));
+  EXPECT_TRUE(cc::SharedBitmap::SizeInBytes(bitmap_size, &size_in_bytes));
   scoped_ptr<base::SharedMemory> bitmap(new base::SharedMemory());
   bitmap->CreateAndMapAnonymous(size_in_bytes);
   memset(bitmap->memory(), 0xff, size_in_bytes);
@@ -76,7 +76,7 @@ TEST_F(HostSharedBitmapManagerTest, TestCreate) {
 TEST_F(HostSharedBitmapManagerTest, TestCreateForChild) {
   gfx::Size bitmap_size(1, 1);
   size_t size_in_bytes;
-  EXPECT_TRUE(cc::SharedBitmap::GetSizeInBytes(bitmap_size, &size_in_bytes));
+  EXPECT_TRUE(cc::SharedBitmap::SizeInBytes(bitmap_size, &size_in_bytes));
   cc::SharedBitmapId id = cc::SharedBitmap::GenerateId();
   base::SharedMemoryHandle handle;
   manager_->AllocateSharedBitmapForChild(
@@ -97,7 +97,7 @@ TEST_F(HostSharedBitmapManagerTest, TestCreateForChild) {
 TEST_F(HostSharedBitmapManagerTest, RemoveProcess) {
   gfx::Size bitmap_size(1, 1);
   size_t size_in_bytes;
-  EXPECT_TRUE(cc::SharedBitmap::GetSizeInBytes(bitmap_size, &size_in_bytes));
+  EXPECT_TRUE(cc::SharedBitmap::SizeInBytes(bitmap_size, &size_in_bytes));
   scoped_ptr<base::SharedMemory> bitmap(new base::SharedMemory());
   bitmap->CreateAndMapAnonymous(size_in_bytes);
   memset(bitmap->memory(), 0xff, size_in_bytes);
@@ -131,7 +131,7 @@ TEST_F(HostSharedBitmapManagerTest, RemoveProcess) {
 TEST_F(HostSharedBitmapManagerTest, AddDuplicate) {
   gfx::Size bitmap_size(1, 1);
   size_t size_in_bytes;
-  EXPECT_TRUE(cc::SharedBitmap::GetSizeInBytes(bitmap_size, &size_in_bytes));
+  EXPECT_TRUE(cc::SharedBitmap::SizeInBytes(bitmap_size, &size_in_bytes));
   scoped_ptr<base::SharedMemory> bitmap(new base::SharedMemory());
   bitmap->CreateAndMapAnonymous(size_in_bytes);
   memset(bitmap->memory(), 0xff, size_in_bytes);